An important part of the new accelerator MESA (Mainz Energy-recovering Superconducting Accelerator) is the beamline connecting the pre-accelerator with the main accelerator. The setup includes a vertical parallel beam offset realized with two dipoles. These are designed in a way, that they can serve as steerer for the main accelerator and will be discussed in this contribution. Furthermore,...
The Large Hadron Collider (LHC) arcs have been designed for a FODO optics with roughly 90° betatron phase advance per arc cell, but not necessarily with exactly the same optics in the eight sectors of the ring. Measuring an optics with a significantly different arc cell phase advance, e.g. 60° which is at the limit for aperture at LHC injection, offers the possibility of understanding the LHC...
750 MHz IH-DTL with the capability to accelerate protons from 3 to 10 MeV was proposed for the compact therpy linac that now under development in IMP. Four drift tube sections were housed in a single vacuum chamber and coupled with three large drift tubes which housing focusing triplet lens inside. In each drift tube section, there were 9 to 10 drift tubes, supported by the separated ridges....
Acceleration of polarized electron and positron beams to ultra-high beam energies is of interests for polarized beam applications in future 100km-scale e+e- circular colliders. However, it was widely envisaged that crossing hundreds of spin depolarization resonances would lead to severe depolarization during the energy ramp in the booster synchrotron. In this work, we have studied the spin...
After the PIP-II linac is commissioned as a new start of the Fermilab Acclerator Complex, the Booster will become a bottleneck for future high intensity particle physics research at Fermilab. An SRF linac is proposed as a replacement for the booster to enable future higher power proton beams in the Fermilab complex - this would include neutrino-based and muon-based studies, dark matter...
Production of super heavy elements of which atomic number is larger than 118 can provide new prospects in the field of nuclear physics. Extremely low production rate of these elements makes the experiments time consuming. This difficulty can be solved by using the energy recovery internal target, so-called ERIT, because the number of interactions can be increased as a circulating beam hits...
To reach the desired energy for a muon collider, muons should be accelerated to 5 TeV. This acceleration must be rapid to avoid muon decays, while simultaneously having a high average bending field to minimize the the required RF voltage. One concern with high energy muons is radiation from neutrinos, produced from muon decay, interacting with matter far from the accelerator. While this is...
This study is motivated by the search for the electric dipole moment (EDM) of elementary particles. The most promising idea in that regard is the “Frozen Spin” concept first proposed by the BNL. This concept, however, requires the building of a brand-new facility devoted to the EDM-search. NICA is not such a facility, hence the need for a modification compatible with the existing optics; one...
I describe a fixed field alternating gradient (FFA) lattice design to accelerate muons final energy for a muon collider. Ideally the muons would be accelerated to 5 TeV to reach the desired energy for physics studies*. An FFA allows the acceleration of muons over a large energy range without changing magnetic fields. It is an alternative to a pulsed synchrotron in which magnet fields must be...
Many applications of synchrotron light sources such as imaging, lithography and angle-resolved photoemission spectroscopy can benefit from high photon flux, which, unlike the brightness, is almost independent of electron beam transverse emittance. To realize high photon flux, it is desired to increase the stored current or number of periods of insertion devices. To this end, a low energy...
Hefei Advanced Light Facility (HALF) was designed as fourth generation light source based on the diffraction-limited storage ring (DLSR). The pre-research has been completely done, due to the smaller beam dynamic aperture, about 10mm, beam inject could not completed by the traditional bump magnet. We purposed and designed a novel dual-channel kicker, with other two traditional kicker, they...
The High Energy Photon Source (HEPS) is a fourth generation photon source, including a storage ring, a booster ring and a Linac. Due to the small dynamic aperture of the storage ring， a novel on-axis swap-out injection scheme was chosen. Here, the 6GeV booster acts as an accumulating ring during that injection process. To extract 6 GeV beam from the booster before injection into the storage...
At MAXIV Laboratory we are continuing the efforts to reduce the emittance of 330 pm.rad of the larger storage ring (SR) operating at an energy of 3GeV. This paper details the techniques used to improve the characterization of the optics, and to optimize the injection into the SR with an emphasis on the difficulties encountered during the process and the strategies adopted to overcome them.
The far-infrared linac and test experiment (FLUTE) serves as an accelerator test facility for a variety of accelerator physics studies. FLUTE is foreseen to provide coherent radiation in ultra-short, very intense light pulses in the terahertz (THz) and far-infrared spectral range. A superconducting undulator in the accelerator structure after bunch compression offers the possibility to...
Betatron coupling resonance has been considered by many low emittance upgrade light sources as a candidate to produce round beams. Due to the limited literature on the topic, last year an experimental campaign was undertaken on the ALBA storage ring to establish limits and requirements to operate a light source in full coupling. The work highlighted how coupling can indeed produce a round beam...
Nowadays, Energy Recovery Linacs (ERLs) became really appealing thanks to their low environmental impact and high sustainability.
ERLs require a special low energy injector, usually named merger. The energy at merger exit is clearly the energy that can’t be recycled in the ERL machine and is the amount dumped at the end. The lower the injection energy is the more efficient is the energy...
Diamond Light Source has been operating in top-up mode for users since late 2008. To date, Diamond’s electron gun has operated in single-bunch mode for multiple-shot top-up of user beam, and multibunch mode for storage ring fill. The uneven bunch-to-bunch charge of the multibunch train is visible in the storage ring and so the fast multibunch fill must be followed by a slower single bunch...
New R\&D concepts for particle acceleration, generation, and focusing at ultra high acceleration gradients (GeV/m and beyond) have the potential to enable future e+e- and $\gamma - \gamma$ colliders to and beyond 15 TeV energies. In addition to proven high gradient and ultra-bright beam generation, these systems have the potential to increase luminosity per unit beam power via short beams, for...
The performance of the Low Energy Ion Ring (LEIR) at CERN is mainly determined by the number of charges extracted from the machine and transferred to the downstream chain of accelerators. While the required target of 9e10 charges has now been surpassed, a series of studies have been undertaken to further push the intensity reach of LEIR. In this work, we quantify the effect of the stray fields...
The nominal Diamond-II storage ring optics have been designed to produce a pseudo twenty-four-fold symmetry by maintaining equal phase advance across the long and standard straights [1]. In this paper, the impact of introducing a high beta section in the injection straight and reducing the ring symmetry to one have been extensively investigated. This solution does not require any additional...
An in-vacuum Hall probe measurement bench was designed, built, and used to measure four Cryogenic Permanent Magnet Undulators (CPMUs) at 77 K at Diamond Light Source. The devices were tuned to correct the phase error at cold temperatures based on the measurements from the in-vacuum bench. The in-vacuum bench consists of a stretched wire system supplied by Danfysik and the in-house Hall probe...
Electron beam central-axis percentage depth dose (PDD) curves in water phantom are routinely employed to evaluate the electron beam energy at the phantom surface, in particular the mean and most probable energies from the values of R50 (half-value range) and Rp (practical range). However, these two quantities are not enough to evaluate important details of the energy distribution, such as the...
The accelerator high-power system provides electromagnetic energy to the acceleration structure to establish a high-power acceleration field. In pace with the current intensity development of accelerator beam, heigtening RF system performance is put on a new agenda. Temperature is a momentous parameter of accelerator RF system, which will directly affect the mechanical, electromagnetic and...
The High Luminosity Large Hadron Collider (HL-LHC) project foresees the upgrade of a large fraction of primary and secondary collimators of the betatron cleaning system to reduce the collimation impedance. The new collimator design also includes the installation of in-jaw beam position monitors (BPMs) to align the collimators faster and to continuously monitor the beam orbit, ensuring an...
While large circular colliders rely upon analysis of turn-by-turn beam trajectory data to infer and correct magnetic lattice imperfection and beam optics parameters, historically storage-ring based light sources have been exploiting orbit distortion, via the orbit response matrix. However, even large collider usually benefit of the orbit analysis during the design phase, in order to evaluate...
Iterative learning control(ILC) is a effictive algorithm for transient beam loading compensation. However, considering the algorithm complexity and the hardware cost, the ILC algorithm is usually implemented outside FPGA. This practice would decrease the real-time ability of the control system. In this paper, a real-time ILC algrithm will be introduced. And the result is summarized.
A third family of sextupole magnets was recently in-corporated at the KIT storage ring KARA (Karlsruhe Research Accelerator). Computer studies of beam dy-namics were performed with an objective to estimate benefits of operation with three sextupole families and possibility of new configuration of ring lattice to con-trol slope and curvature of momentum compaction factor as function of energy...
A 7 MeV Alvarez-type drift tube linac (DTL) had been designed and machined in the past few years for Xi'an 200 MeV proton application facility (XiPAF). This paper presents the assembly, alignment, error analysis and tuning results of the DTL. After all these tasks were completed at Tsinghua University, the DTL cavity had been transported to Xi'an for repetition measurement and test. It has...
All high-energy beam dump events at the Large Hadron Collider (LHC) are analysed to verify correct functioning of the Machine Protection System and to allow early identification of potential issues. This includes the evaluation of particle losses before and during the beam dump event.
The paper describes a newly developed tool for the automated evaluation of beam losses during high energy...
RF-Conditioning of a room temperature cavity is a long and resource intensive process. The need for constant supervision by experienced personal to avoid damage to the cavity and used equipment makes it a very expansive endeavor. To reduce the workload of the experimentalist, it was decided to develop a program utilizing machine learning, which, once finished, should have the probabilities to...
A lattice of a storage ring for the future plan of UVSOR synchrotron facility, UVSOR-IV, is designed at 1 GeV electron energy. The lattice of 12 compact double achromat cells conducts to an emittance of 4.2 nm at 1 GeV electron energy and 2.3 nm at 750 MeV electron energy in achromat condition, 82.5 m circumference, and six straight sections of 4 m long and six of 1.5 m long. The lattice has...
We fabricated corrugated wakefield structures and did cold test of them. Since the wakefield frequency of our structure is about 0.2 THz, there are several technical issues in the bead-pull.
We present issues concerning to bead size and the wire. And issues concerning to mode converter are described as well. We manufacture a customized mode converter which change electromagnetic mode from...
The baseline beam parameters of the FCC-ee contemplate different operation modes, with beam energies ranging between 45.6 GeV and 182.5 GeV. The highest expected beam stored energy reaches 20 MJ for the so-called Z operation mode (45.6 GeV), i.e. two orders of magnitude above that found in previous and operating lepton colliders.
In order to protect sensitive equipment and to limit...
The Beijing Electron Positron Collider II will upgrade to achieve a higher beam energy and higher luminosity which need a higher beam current and smaller beam size. The consequent high beam background should be controlled within in a safety range. The beam related background at BEPCII is mainly from the Touschek effect and the beam gas effect. This paper presents the beam background study at...
The machine-detector interface (MDI) issues are one of the most complicated and challenging topics at the Circular Electron Positron Collider(CEPC). Comprehensive understandings of the MDI issues are decisive for achieving the optimal overall performance of the accelerator and detector. The CEPC machine will operate at different beam energies, from 45.5 GeV up to 180 GeV.
A flexible...
Due to various errors, the beam does not pass through the center of magnets in a storage ring. The beam orbit is affected by additional dipole fields since magnetic field feed-down. To obtain a reference orbit, on which the beam circulates along the quadrupole axes, the beam-based alignment (BBA) is performed in the ring. In this work, a novel method based on a neural network is proposed to...
After the successful conclusion of Run1 in 2018, the AWAKE experiment is presently undergoing its second phase (Run2), which aims to demonstrate the possibility of producing high quality electron beams for high energy physics applications.
Over the last year, a significant time-investment was made to study proton beam centroid modulation effects in plasma induced by a seeding electron bunch...
Heavy-ion single event effect (SEE) test facilities are critical in the development of microelectronic components that will be exposed to the ionizing particles present in the hostile environment of space. CHARM High-energy Ions for Micro Electronics Reliability Assurance (CHIMERA) and HEARTS have developed a high-energy ion beam capable of scanning a wide range of Linear Energy Transfer (LET)...
The Large Hadron Electron Collider (LHeC) is a study at CERN to construct an energy recovery linear accelerator (ERL) tangentially to the High Luminosity Large Hadron Collider (HL-LHC). This would enable deep inelastic scattering collisions between electrons and protons in the ALICE interaction region (IR2). In this design, one of the two proton beams of the HL-LHC collides with the electron...
The electron-positron Future Circular Collider (FCC-ee) foresees stored beam energies up to 20.7 MJ, a value almost two orders of magnitude higher than any previous lepton collider. Considering the intrinsic damage potential of the FCC-ee beams, a halo collimation system is under study to protect the most sensitive equipment from unavoidable losses. Beam dynamics and tracking studies are key...
A high-charge, low-emittance injection beam is essential for SuperKEKB. For its both rings, HER and LER, the injection efficiencies and detector backgrounds have not been good enough up to the recent run. There are many reasons for the issues. For example, serious emittance growths are observed through the beam transport lines between the injector linac and both rings. It is considered...
The single nonlinear kicker (NLK) injection has been adopted by several synchrotron radiation light source facil- ities or their upgrades. The injected beam receives a kick from an NLK and goes into the acceptance of the storage ring while the stored beam passes through the center of the NLK where the magnetic field is almost zero. Compared with the local-bump injection, NLK injection requires...
Compared to the conventional injection scheme, the three-kicker bump injection scheme with an anti-septum has two advantages. One is less requirement of dynamic aperture thanks to the thin blade of the anti-septum, the other is less installation space requirement of the injec-tion system. Both are beneficial to the beam injection for the fourth generation light sources. In this study, the...
In the electron-driven ILC positron source, the positron is generated a multi-bunch format with gaps, because it corresponds to a part of the damping ring fill pattern. The beam loading is compensated by amplitude modulation on the input RF (*). In this article, we derive the exact solution for the compensation with gaps. In addition, we evaluate the effect of the time constant (delay) of the...
The Insertion Region 2 (IR2) will accommodate a Pre-Cooler at injection energy ($24~\mathrm{GeV}$) and a Strong Hadron Cooling
(SHC) facility at top energy ($100~\mathrm{GeV}$ and $275~\mathrm{GeV}$) in the Hadron Storage Ring (HSR) of the Electron-Ion Collider
(EIC). This paper summarizes the lattice update in HSR-IR2 to meet the requirements from the Pre-cooling and the SHC. The layout...
The proposed REDTOP experiment is a $\eta$/$\eta'$ factory aiming to explore dark matter and physics beyond the Standard Model. The $\eta$ and $\eta'$ mesons are almost unique in the particle universe because of their quantum numbers and the dynamics of their decay are strongly constrained. This effect increases the branching ratio of rare decays which can be studied to probe physics BSM. The...
In the future 100 km-scale Circular Electron Positron Collider (CEPC), beam polarization is an important design aspect. Transverse beam polarization for resonant depolarization is essential for precision measurements of the beam energies at Z-pol and WW threshold. Longitudinally polarized colliding beams are also beneficial for expanding the capability of the physics program. This paper...
Wuhan Advanced Light Source (WALS) is a fourth generation diffraction limit synchrotron radiation facility, which is composed of a full energy 1.5 GeV LINAC, a 1.5 GeV Storage Ring and 10 beamlines for its phase I project. The LINAC is 6 meters lower than the storage ring, which is connected by a 46 meters beam transfer line. The beam transfer line includes three parts, one ver-tical line...
Large initial beam position monitor (BPM) offsets have to be reduced by one order of magnitude by means of beam-based calibration (alignment) (BBA) in order to match the element-to-element magnet alignment error. At SLS 2.0 the BBA will be performed with respect to adjacent auxiliary quadrupole magnets, which are also employed for optics and tune correction. Different static and dynamic...
Top-up operation at BESSY II is performed with average injection efficiencies of 98 %. However, the four-kicker bump and the septum, that form the present injection system, both contribute to a distortion of the stored beam with an amplitude of about two millimeters for several thousand turns after injection. A non-linear injection kicker (NLK) could be used to reduce the distortion due to the...
The understanding of beam-beam effects, which influence the choice of the FCC-ee design parameters for several aspects, require sophisticated and high-performance numerical simulations. The self-consistent study of the interplay of nonlinear dynamical phenomena resulting from collisions in the machine is key to accurately assess its potential performance. Although current simulation frameworks...
For the Future Circular Collider (FCC-ee), particular attention is drowned to the crucial role of the positron source. Two positron production schemes are considered for the FCC-ee: conventional and crystal-based (hybrid), implying the use of channeling radiation in the oriented crystals. To design and optimize the positron production and capture by considering the positron injector...
To harness the major advances that have been done in the field of synchrotron light research, Elettra synchrotron radiation facility is being updated. Presently in its design phase, the Elettra 2.0 project will allow new and better research to be performed at the facility. In the upgrade of the storage ring, the new 6BA lattice brings challenges in terms of available space and radiated power....
The “Pre-Conceptual Design Report” (preCDR) of the BESSY III facility (https://doi.org/10.5442/r0004) has been finalized at the end of August 2022 and reviewed by a Project Advisory Committee beginning of September 2022. In this paper, we give a status report of the BESSY III facility project and will discuss aspects of lattice design, technical specifications, initial developments and a first...
The measurement of Bhabha scattered leptons enables a direct estimate of luminosity in lepton colliders. Currently existing Monte Carlo event generators for this process are optimized for high precision detector background simulations. From a beam dynamics point of view, emitted photons will modify the bunch distribution and lead to beam losses
due to the limited momentum acceptance of the...
The Southern Advanced Photon Source is a diffraction-limited storage ring at middle energy. The popular injector which includes a low energy Linac and a full energy booster is proposal. The concept design of the booster is presented in the paper. The booster is a high intensity synchrotron accelerator. The impedance model is obtained and the instability threshold is predicted.
Due to the reduced diameters of the vacuum chambers and of the other equipment, the performance of the next generation light sources can be greatly affected resulting in a reduction of the intensity in both single and multi-bunch operations. This is particularly important for Elettra 2.0 since there are plans to incorporate bunch compression schemes for providing very short photon pulses. In...
At SPring-8, the injector was changed from the booster synchrotron to the XFEL linear accelerator. Accordingly, we have developed a new bunch cleaning system in the storage ring to ensure high bunch purities required by photon beam users since unwanted electrons were observed behind the injection bunch even after some countermeasures were taken in the injector to eliminate unwanted electrons....
We carried out the study of the beam lifetime at SuperKEKB to investigate beam instabilities. We analyzed the injection interval for individual bunches to evaluate their beam lifetime ratio. SuperKEKB performed the top-up operation with the equalized bunches currents. This particular condition enables us to evaluate the lifetime ratio among all operation bunches. This report introduces the...
Inverse Compton Scattering is a promising technique to deliver compact, high brightness and high rate sources of photons ranging from few keVs to several MeVs. Current projects either focus on producing high rates of photons thanks to high-power (up to 300kW) enhancement optical cavities and electron storage rings or on providing low bandwidth photon sources based on room-temperature linacs....
NICA is mainly designed for experiments with heavy ions and polarized proton and deuteron beams at an energy of the former about 13 GeV. For these purposes, appropriate SPD and MPD detectors, as well as other necessary implements, are installed in the straight sections. EDM experiment supposes use deuterons at an energy of about 240 MeV. To ensure the «Quasi-Frozen Spin» mode, E+B elements...
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is one of the most powerful accelerator-driven neutron sources in the world. The intense protons strike on SNS’s mercury target to provide bright neutron beams, which also leads to severe fluid-structure interactions inside the target. Prediction of resultant loading on the target is difficult particularly when helium gas is...
I describe the method used for calibration the amplitudes and phases of the cavities in the Main Linac Cryomodule (MLC) for the CBETA energy recovery linac at Cornell University. The cavities are powered one at a time, and the phase of each cavity is set to a uniformly spaced set of values over a full 360 degree range, with cavity voltages set to one or more values. For each cavity, voltage,...
Optical enhancement cavity (OEC) provides the high intensity and high stability modulation laser field in steady-state microbunching (SSMB) light source. An SSMB extreme ultraviolet (EUV) light source targeted for lithography application is currently being developed at Tsinghua University, which demands for megawatt scale intra-cavity power for OEC. Cavity mirrors are the key components of the...
Extending the energy reach of CEBAF by increasing the number of recirculations, while using the existing linacs is explored. This energy upgrade is based on the multi-pass acceleration of electrons in a single non-scaling Fixed Field Alternating Gradient (FFA) beam line, using Halbach-style permanent magnets. Encouraged by the recent successful demonstration of CBETA, a proposal was formulated...
The CEPC is a proposed high luminosity Higgs/Z factory, with the potential to be upgraded to top factory at center-of-mass energy of 360GeV. We perform an optimization study on the circumference of CEPC. We calculate the instant luminosity, the construction and operation cost for different circumferences. With respect to the total cost and average cost per particle, we conclude that the...
A damping ring system which includes a small 1.1 GeV ring and two transport lines is introduced in CEPC linac in order to reduce the transverse emittance of positron beam at the end of linac and hence reduce the beam loss in the booster. The repetition rate of Linac is 100 Hz and one-bunch-per-pulse is considered. The double-bunch scheme of Linac is only considered for the high luminosity mode...
The future upgrade to the High-Luminosity Large Hadron Collider (HL-LHC) will impose tight tolerances on IP optics measurements. k-modulation is currently the preferred method in the LHC for IP optics measurements and will play a critical role in the HL-LHC. As such, Run 3 of the LHC provides an ideal test-bench for addressing challenges in k-modulation. In the first commissioning year of Run...
I describe a method for finding a set of cavity voltages and phases for the CBETA multi-pass energy recovery linac. The beam in CBETA makes up to 8 passes through its 6 cavity linac. The voltage and phase for each cavity can be set individually, and the path length for each arc energy can be set as well. I show that solutions can be found where each cavity has energy gains and losses balanced...
The Electron-Ion Collider (EIC) uses the local crab crossing scheme to compensate the geometric luminosity loss of the $25 ~\mathrm{mrad}$
crossing angle in the interaction point. Due to space limitations and other optics constraints, the beam optics at the crab cavities in
the Hadron Storage Ring (HSR) is not perfectly matched to fully compensate the crab dispersion.
This paper...
The fourth generation of synchrotron radiation sources will be constructed in Wuhan. The RF system of the storage ring provides 600kV voltage to the beam through a 500MHz normal conducting cavity. A coaxial coupler is designed for the 500 MHz cavity to input 150kW power. The coupler was modified from KEK-B. We use a high-power ceramic disk window design and under over cut window structure....
The High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC) aims to achieve stored beam energies of 680 MJ. One possible limit to the achievable intensity is the quench limit of the superconducting magnets downstream of the betatron collimation insertion. At HL-LHC beam intensities, even a tiny amount of particles leaking out of the collimation system may be sufficient to quench...
For the Future Circular Collider (FCC) Conceptual Design Report (CDR), the FCC-hh collimation system was studied and optimized for proton and heavy-ion operation with up to 8.3 GJ stored beam energy. There are currently studies ongoing for an updated design baseline, including a new ring layout, compatible with the FCC-ee, and optics, where the collimation insertions have undergone major...
Magnetic fields in the 12-16 T range are needed to bend the beams in future hadron colliders, such as the CERN FCC-hh. For these magnets, made with Nb3Sn superconducting cable, a small reduction of the field brings a non-negligible reduction of cost and complexity. Increasing the dipole filling factor is hence a priority to provide higher energies for the same magnetic fields - or the same...
The RF system of the ThomX storage ring consists in a 500 MHz single cell copper cavity of the ELETTRA type, powered with a 50 kW CW solid state amplifier, and its associated Low-Level RF feedback and control loops. The low operating energy of 50 MeV makes the impedances of the cavity higher order modes (HOMs) particularly critical for the beam stability. Their parasitic effects on the beam...
We will report on the ongoing ThomX ring commissioning, its status, its main challenges, our results and our planning.
ThomX is a compact Compton-based X-ray source under commissioning at IJCLab in Orsay (France). This facility is composed of a 50-70 MeV linac, a transfer line and a storage ring whose closed orbit is 18 m long. Compton scattering between the 50 MeV electron bunch of 1 nC...
Storage ring commissioning-like simulations are necessary to assess the feasibility of proposed future lattice designs. This paper proposes a python package for commissioning-like simulations based on python accelerator toolbox (pyAT). The software includes: 1) errors definition, 2) correction routines from open trajectory to optics and coupling correction and 3) the evaluation of the relevant...
Hollow electron lenses (HELs) could be used in the HL-LHC to selectively remove halo particles from the circulating beams. While the ideal design should leave particles in the beam core unaffected, in reality, the core particles will be exposed to a small residual kick that could induce transverse emittance blowup if not properly compensated while the HEL is operated in pulsed mode. One...
The interaction of particle beams with materials is important for muon colliders, as it causes particle scattering, energy loss and energy-straggling processes. Such interactions are also relevant in high-precision applications such as radiation oncology treatment planning, where the beam travels through air before reaching the patient, and are also the crucial mechanism for ionization cooling...
Modern synchrotron light sources are competing intensively to increase X-ray brightness and, eventually, approach the diffraction limit, which sets the final goal of lattice emittance. Recently, we propose a new optics solution aimed at reaching low emittance, using a lattice element “Complex Bend”. The Complex Bend is a sequence of dipole poles interleaved with strong alternate focusing so as...
We presented a novel concept of longitudinal bunch train compression capable of manipulating relativistic electron beam in range of hundreds of meters. It has potential to compress electron beam with high ratio, and raise its power to ultrahigh level within compressed duration of nanoseconds. Electron’s spiral motion in uniform magnetic field is utilized to fold the hundreds of meters long...
The SHADOWS experiment is a proposed beam dump experiment in the CERN North Area, aiming to search for feebly interacting particles (FIPs) created in 400 GeV/c proton interactions. Due to its intended off-axis location alongside the K12 beam line, the SHADOWS detector can be placed potentially very close to the dump, enabling it to look for FIPs in non-covered parts of the parameter space. To...
The Configuration Management of the LHC and its injectors ensures a clear and coherent representation of the CERN accelerators at a given point in time. It has been evolving steadily. The methodology has been continuously improved, incorporating best practices and was also extended to the injectors to face the Long Shutdown 2 (LS2) with a set of rigorous and homogenised processes for the...
The current injector complex design of the FCC-e+e− project consists of e+/e− linacs, which accelerate the beams up to 6 GeV, a damping ring at 1.54 GeV, a pre-booster ring, accelerating the beam up to 16 GeV and a booster synchrotron ring integrated in the collider tunnel accelerating the beams up to the collision energies. The purpose of the damping ring is to accept the 1.54 GeV beam coming...
Commissioning a test beamline in KEK Photon Factory Advanced Ring (PF-AR, 6.5GeV and 5.0GeV) is proceeded under cooperation with the KEK Institute for Particle and Nuclear Studies (IPNS) to use electron beams in the GeV-range for the development of detectors in particle physics experiments. The inauguration of the project which was mainly directed by the IPNS was launched back in 2014, but the...
Coordinate conversion is used in many aspects, such as laser tracker transfer problem, the conversion between WGS84 coordinate system and local coordinate system and so on. The high precision of coordinate conversion model is beneficial to improve the accuracy index of the network. The dual quaternion can integrate rotation and translation, which effectively simplifies the complexity of the...
In this paper we present the first results of full 6D multi-bunch tracking through the new Drive-Beam decelerator lattice for the first-stage of the Compact Linear Collider (CLIC). Using the new PLACET3 tracking code, we evaluate the coupling between transverse and longitudinal dynamics in the lattice finding an indirect impact of the Drive-Beam's transverse emittance in the Main-Beam performance.
Over the last three years (2020-2022) Diamond Light Source has installed four in-house designed, built, and measured Cryogenic Permanent Magnet Undulators (CPMUs). All four are 2 m long with a 17.6 mm period and have a minimum operating gap of 4 mm. These have replaced existing 2 m long in-vacuum pure permanent magnet (PPM) devices to improve the flux to several of Diamond’s MX (Macromolecular...
Crystal collimation is studied to improve the collimation efficiency with ion beams at the High-Luminosity Large Hadron Collider (HL-LHC). Bent crystals are used instead of conventional primary collimators to deflect high-energy halo particles at angles orders of magnitude larger than what can be achieved with scattering by conventional materials. Following the promising results obtained...
DAFNE, the Frascati electron-positron collider, based on the Crab-Waist collision scheme, has successfully completed the preliminary phase with the SIDDHARTA-2 detector aimed at testing and optimizing the performances of the machine and the experimental apparatus.
In this configuration the collider has delivered to the experiment, using gaseous 4He targets, a data sample suitable to perform...
The Future Circular Collider project is built around two main pillars: the construction of 100 km lepton collider running at increasing energies from the Z-pole to the t-tbar threshold (FCC-ee) followed by a hadron collider in the same tunnel (FCC-hh) to explore unprecedented energy frontier.
The realization of FCC-ee relies on a very challenging injector complex that should provide the...
We discuss the beam requirements for indirect searches of dark matter and feebly coupled particles using advanced accelerator concepts. A parameter comparison reveals dielectric laser acceleration as a promising candidate for delivering the needed single-electron beams in the 5-100 GeV energy range or beyond. We suggest a parameter set for a baseline DLA-based dark sector accelerator....
An MeV ultrafast electron diffraction (MUED) instrument system, such as is located at the Accelerator Test Facility (ATF) of Brookhaven National Laboratory, is a structural characterization technique suited to investigate dynamics in the ultrashort range in a variety of materials via a laser pump method. It is a unique characterization technique especially suitable for highly correlated...
After the discovery of the Higgs boson at the LHC, particle physics community is exploring and proposing next accelerators, to address the remaining open questions on the underlying mechanisms and constituents of the present universe. One of the studied possibilities is FCC (Future Circular Collider), a 100-km-long collider at CERN. The feasibility study of this future proposed accelerator...
A degrader device is being built at the CEBAF injector to degrade the electron beam phase space for machine acceptance studies. The electron beam is degraded through multiple scattering in a thin target before further transport in the injector beamline for injection into CEBAF. The degraded electron beam will approximate phase space distributions expected from a bremsstrahlung-based polarized...
Within the Standard Model the electric dipole moment (EDM) of the muon is heavily suppressed. Observation of a non-zero EDM value would be an additional source of CP violation that would aid in answering the many open questions about the universe and the Standard Model. As part of an investigation into the feasibility of measuring the muon EDM at the g-2 storage ring at Fermilab, a study on...
The main SPS users are the experiments installed in North
experimental Area (NA) which are served with a continuous 4.8 s long
spill of protons and heavy ions. A third-integer resonant slow extraction is used to provide a uniform, long spill. Such a technique
comes at the cost of particles directly hitting the electrostatic septum
wires and activating the surrounding of the extraction...
In the J-PARC Muon g-2/EDM experiment, to measure muon g-2 and EDM, it is necessary to accumulate 300 MeV/c muon beams with a 66 cm diameter region with a 3 T solenoid-type magnetic field. A new three-dimensional spiral injection scheme has been invented to achieve this target. Since this is the first instance to employ this injection scheme, a scale-down experiment with an electron beam of...
Nb3Sn, NbTiN and NbN are superconductors with a critical temperatures of 18.3, 12.6-17, 11.6-17.5 K, respectively, that are higher than that of Nb (9.3 K). Hence, at 4 K they have an RF resistance of an order of magni-tude lower than that of Nb, which leads to quality factors above those of Nb. In recent years, there has been an extensive effort converting Nb cavities into Nb3Sn by alloying...
CNAO is one the six hadrontherapy centers all around the world that produce
both proton and carbon
ions beams.
It is based on a synchrotron in which the beams are extracted by a slow extraction mechanism that uses a betatron core.
In the last years an electrostatic exciter has been installed along the ring in order to allow
beam extraction using the RF-KO method.
The system has been...
The Spallation Neutron Source (SNS) employs six cavities in the Drift Tube Linac (DTL) section to accelerate the H- ion beam to 87MeV. Each cavity is energized by a 2.5MW peak power klystron at 402.5MHz using rapid tapered waveguide iris couplers. All six original iris couplers have been in operation without replacement for over two decades. The increased RF power demands of the Proton Power...
A test station for the THALES 300kW transmitter PSM has been successfully constructed in NSRRC. Integrating the modules of power supply, control interface, interlock protection, and accessories into a single rack simplifies the examination procedure and makes signal observation easier. The layout and hardware realization of this test station, as well as important considerations and proper...
The Future Circular electron-positron Collider (FCC-ee) is planned to operate with beam energies from 45.6 to 182.5 GeV and beam currents from 5 to 1400 mA. This will enable precision physics at the four operational points, Z, W and Higgs boson and the top and anti-top quarks. This work will focus on the RF structure design for the ttbar operation point to reach a beam energy and current of...
**The baseline scheme for hadron beam cooling in the Electron Ion Collider (EIC) calls for Coherent electron Cooling (CeC) of the hadrons with non-magnetized electrons at high energy (150 MeV electrons), and additional cooling via conventional bunched beam cooling using a precooler system. The electron beam parameters for these concepts are at or beyond the current state of the art, with...
this paper briefly introduces the layout theory and analysis basis of the first-level control network, calculates the accuracy index of the first-level control network of Hefei Advanced Light Source, designs the basic scheme of the first-level control network, and analyzes the absolute precision and relative precision of the control network in detail through the simulated adjustment...
In the Electron Ion Collider (EIC), to be built at Brookhaven National Lab, the beams collide with a crossing angle of 25 mrad and an aspect ratio of 12 to 1. The orbit control in the interaction region is critical to achieve and to maintain the design luminosity and polarization, and to control synchrotron radiation induced detector background. In his report, the authors will introduce the IR...
High brightness beams are desired for application to Inverse Compton Scattering (ICS) systems for generation of high-quality x- and γ-rays. It opens new opportunities for nuclear physics research in fields such as nuclear photonics, nuclear astrophysics, photo-fission, production of exotic nuclei, applications in medicine, industry and space science. In ICS mechanism high energy electron is...
LEAF (Low Energy heavy ion Accelerator Facility) is a low-energy high-intensity heavy-ion LINAC complex for multidiscipline research. At present, the beam repetition rate is the same as the LINAC frequency of 81.25 MHz. A lower frequency would be desirable for many types of experiments employing time of flight data acquisitions. A method of increasing the bunch spacing to 98 ns by combining a...
The Southern Advanced Photon Source (SAPS) is a 4th generation storage ring based light source under design started several years ago, which is planned to be constructed
at Guangdong province at China. The equilibrium emittance of the storage ring will be below 100 pm.rad and the beam energy is determined to be 3.5 GeV. During the past two years, the nominal current of the storage ring was...
We propose to develop a compact superconducting cyclotron to accelerate H2+ ions for isotope production since using H2+ allows the use of a stripper foil after extraction from the cyclotron to remove the binding electron, thereby doubling the electrical beam current. An RFQ, partially embedded in the cyclotron yoke, will be used to bunch and axially inject the H2+ beam into the cyclotron’s...
Super Tau Charm Facility (STCF) proposed in China, is a future electron-positron collider project with symmetric double ring. It’s designed to be operated in the center of mass energy (CME) range between 2 GeV and 7 GeV. The goal luminosity is beyond $0.5\times 10^{35} cm^{-2} s^{-1}$. Hybrid multi-bend-achromat (HMBA) concept, proposed to develop low emittance lattices with large dynamic...
The Super Proton Synchrotron (SPS) injection system plays a fundamental role to preserve the quality of injected high-brightness beams for the Large Hadron Collider (LHC) physics program and to maintain the maximum storable intensity. The present system is the result of years of upgrades and patches of a system not conceived for such intensities and beam qualities. In this study, we propose...
As compared to traditional magnets, permanent magnets can effectively reduce energy consumption and eliminate the impact of current ripple and the wa-ter cooling system on beam current. The use of perma-nent magnets in accelerators has become a new trend as permanent magnet technology has advanced. In HALF, we have designed a permanent magnet based on the quadrupole magnet, and the central...
A S band high power klystron for BEPCII operating at frequency of 2856 MHz has been designed and simulated at Institute of High Energy Physics, Chinese Academy of Sciences. A thermionic electron gun have been designed. A beam current of 379 A is obtained at operating voltage of 325 kV with cathode current density of 6.6 A/cm2. Then, the full 3-dimensional particle-in-cell simulation of the...
High power input often leads to frequency deviation that cannot meet the high-precision frequency control requirements of keV Ultrafast Electron Diffraction (UED) compression cavities. In this paper, we propose new solu-tions for reducing heat generation and frequency devia-tion based on modifications to the cavity design and power input method, building upon the design of the orig-inal...
The Compact Linear Collider (CLIC) is a proposed linear accelerator designed to collide electrons and positrons at energies up to 3 TeV. In order to explore new physics and to be more competitive with other collider projects, CLIC is exploring the increase of the center-of-mass energy to 7 TeV. The CLIC Beam Delivery System (BDS) transports the lepton beams from the exit of the Main Linac to...
Presented in this paper is the beam optics design of the final focus system (FFS) for the Super tau charm facility (STCF) in China, which is an electron positron circular collider with center-mass-energy (CME) from 2 GeV to 7 GeV. To achieve a luminosity of more than $ 5 \times 10^{34} cm^{-1}s^{-1}$, FFS with Large Piwinsky angle and crab waist scheme.
The Advanced Wakefield Experiment (AWAKE) has demonstrated during its first run (Run1, concluded in 2018) the capability of accelerating electrons up to the energy of 2 GeV using proton driven plasma wakefield acceleration.
AWAKE Run 2 has started and during the third phase of the program, Run 2c, which aims to demonstrate stable accelerating gradients of 0.5-1 GV/m and emittance...
With the growing interests and new experimental development in time-resolved studies at Stanford Synchrotron Radiation Light Source (SSRL), we are motivated to develop the Pseudo Single Bunch (PSB) operational mode to address the requirements from time-resolved and regular user experiments simultaneously. In this paper, we will present the physics design for this new mode. Beam line...
The High Energy Photon Source is a 6 GeV synchrotron radiation light source being built in Beijing, China. The electron beam inside the storage ring is designed to run with ultra-low emittance. To ensure high beam quality, the coupled bunch instabilities must be carefully investigated and controlled, therefore an effective feedback system is essential. Stripline kickers are designed for...
A Boron Neutron Capture Therapy facility requires a high flux of neutrons (approx. 10^9 thermal or epithermal n/s*cm^2) with low contamination content (gamma and off energy neutrons). The core of such a facility is a low energy high intensity proton linac, coupled with a high power beryllium neutron production target, followed by a proper Beam Shaping System. In this paper we shall discuss...
Based on the key scientific questions in the frontier of particle physics field, the current status and future development trend globally and domestically of accelerator-based particle physics experiments, a Super Tau-Charm Facility (STCF) is proposed by taking into account the advantages in the relevant fields in China. The STCF is a new-generation electron-positron collider facility that has...
A new fourth-generation synchrotron radiation source(4GSR) will be built in Ochang, South Korea by 2027. A technical design review for the Korea 4GSR is currently in progress and is expected to be completed in mid-2023.
The storage ring has a circumference of 800 m. It has been designed for a maximum current of 400 mA at 4 GeV electron beam energy. A target emittance is 58 pm-rad, 100 times...
The Electron-Ion Collider is gearing up for "Critical Decision 2", the
project baseline with defined scope, cost and schedule.
Lattice designs are being
finalized, and preliminary component design is being carried out. Beam dynamics
studies such as dynamic aperture optimization, instability and polarization
studies, and beam-beam simulations are continuing in parallel. We report on
the...
In order to produce a high luminosity at the interaction point, the Compact Linear Collider (CLIC) accelerators must preserve low emittance beams along both the main 22km linacs. A key factor in preserving a low emittance beam is the mechanical alignment and stability of the accelerator components.
The CLIC accelerators are divided into `Two Beam Modules’ (TBMs) which integrate a section of...
The FFA@CEBAF energy upgrade study aims to approximately double the final energy of the electron beam at the Continuous Electron Beam Accelerator Facility (CEBAF). It will do this by replacing the highest-energy recirculating arcs with fixed-field alternating gradient (FFA) arcs, allowing for several more passes to circulate through the machine. This upgrade necessitates the re-design of the...
MYRRHA will be a research infrastructure focussed on the construction of a first prototype of an accelerator driven sub-critical nuclear reactor (ADS). The driver ac-celerator will deliver a 600 MeV, 4 mA Proton beam to the reactor core. The first phase called MINERVA aims for the construction of a 100 MeV, 4 mA proton linear accel-erator with a focus on reliability. Attached to this 100 MeV...
The Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBL) is going through an upgrade (ALS-U), where the ALS triple-bend achromat is replaced by a nine-bend achromat storage ring (SR) with on-axis injection using beam swapping from a triple-bend achromat accumulator ring (AR). The small beam size at the straight sections of the ALS-U has opened the possibility to use...
With the high accelerating gradient, radiofrequency (rf) gun has a significant feature of suppressing the growth of transverse emittance caused by space charge. Field emission cathodes were first used in vacuum electronic devices, which do not require the high electron beam intensity, but the cathode size and integrality. A new X-band (11.424 GHz) rf electron gun has been proposed with the...
Manipulating high energy beams with bent crystals has applications ranging from beam collimation to slow or direct beam extraction. These systems are now integrated parts of accelerators and studied for future experimental set-ups.
With growing achievements and expectations of crystal beam manipulation, requirements for the devices that operate the crystals become more stringent. They must...
Beam-based alignment (BBA) is a standard tool at accelerators for aligning particle beams to the centre of quadrupole magnets. Traditional BBA measurements have been slow, potentially taking many hours for a whole machine. We have developed a tool, based on results previously reported at the ALBA synchrotron, that uses fast excitation of magnets to greatly speed up measurements. We show...
Southern Advanced Photon Source (SAPS) is a 3.5GeV fourth-generation storage ring light source, considered to construction in Guangdong province of china, adjacent to the China Spallation Neutron Source(CSNS). Its natural emittance of the beam is close to the diffraction limit. Since the dynamic aperture of SAPS is far smaller than the physical aperture in the low emittance storage ring,...
The PETRA IV storage ring currently under development at DESY will require a third harmonic 1.5 GHz RF-system to prevent negative effects on both, lifetime and emittance, caused by Touschek effect and Intrabeam scattering. These cavities lengthen the bunches and thereby reduce their charge density.
For this 3rd harmonic system, a one-cell single-mode cavity with a simple mechanical and...
The muon-dedicated linear accelerator is being developed for the muon g-2/EDM experiment at J-PARC. To suppress the decay loss during acceleration, the alternative phase focusing (APF) method inter-digital H-mode drift tube linac (IH-DTL) is adopted in the low-velocity region following a radio-frequency quadrupole linac (RFQ). We are planning to accelerate muons in 2024 using the RFQ and the...
MINERVA (MYRRHA phase 1) aims at demonstrating the requirements related to the reliability and the fault tolerances of the MYRRHA accelerator-driven system (ADS) by the realization of a superconducting linac for 100 MeV/4 mA proton beams. The design and the performance of the Medium Energy Beam Transfer section (referred to as MEBT-3) of the accelerator are critical for reaching the goals of...
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34cm^{-2}s^{-1} in the center mass energy range of 20-140 GeV. Besides high luminosity and high polarization, it is also recommended for the EIC design to incorporate a possible second interaction region...
The Electron-Ion Collider (EIC) will be constructed at Brookhaven National Laboratory with the goal of providing high luminosity, high average beam polarization, and a wide range of colliding beam energies. One critical requirement is a large dynamic aperture (DA) of the collider rings, in both transverse and momentum dimensions. The ring lattices have been continually optimized to improve the...
The PETRA IV project will have a storage ring with an ultra-low natural emittance of 20 pm rad [1]. For an off-axis injection scheme with working points at the difference resonance it is important to assure the vertical excursion arising due to transversal coupling such, that injection efficiency is not compromised. In this contribution we present simulations results of an off-axis injection...
We frequently experience earthquakes in Japan. Even though countermeasures against earthquake is deeply considered and well carried out, sometime troubles are occurred on facilities or experimental devices. When we focus on the relative displacement due to an earthquake, it is possible to cause damage of a beam pipe bellows or interference by disappearing tolerance between the sub-detectors....
Proton bunches will collide with electron bunches in the Electron-Ion Collider (EIC) to produce a luminosity of up to $10^{34}~\mathrm{cm}^{-2}\mathrm{s}^{-1}$. Various sources can lead to electron orbit ripple at the interaction point (IP). This ripple will cause emittance growth of the proton beam via beam-beam interaction. This paper presents weak-strong simulations for the case where a...
The FEL performance strongly correlates with the undulator field quality. The definition of mechanical tolerances for the undulator magnets allows us to achieve the wished field quality. These mechanical tolerances should be defined both on short and long-range errors. With long-range errors, we address problems like deformations of the yoke caused by the support structures or unwanted...
The Electron Ion Collider is adopting a crabbing scheme of 25 mrad crossing angle. The local crab cavity system designed to kick the bunches in the first interaction region (IR) also introduces higher order multipoles com-ponents in electric field which affect the dynamic aperture. We have studied the strength of each multipole up to n = 4, or octupole, with respect to the main dipole field in...
An electromagnetic chopper is an important component of particle accelerators. It helps to provide users with different time structure beams. It is usually placed in the low energy beam sections of accelerators. In general, the chopper has rise and fall times of the order of a few nanoseconds. Due to this rise and fall time, post-chopper beam dynamics are affected. As part of this master...
A scheme for electron acceleration by self focused -Gaussian laser pulses in under dense plasma has been presented. The relativistic increase in the mass of plasma electrons gives nonlinear response of plasma to the incident laser pulse resulting in its self focusing. Under the combined effects of saturation nature of relativistic nonlinearity of plasma, self focusing and diffraction...
Polarization levels in the Electron Storage Ring (ESR) of the Electron-Ion Collider (EIC) must be maintained for a sufficient time before depolarized bunches are replaced. The depolarizing effects of synchrotron radiation can be minimized with spin matching, however the optics requirements for the ring must still be satisfied. Furthermore, the robustness of the polarization in the presence of...
The EIC electron beam parameters will feature 320 kJ stored kinetic energy and beam sizes leading to the melting of most metals in case of normal impact of a single bunch. In order to protect the aperture, focusing magnets and experimental detectors from beam losses and backgrounds a dedicated collimation system will be included in IR2 and IR4. Additionally, to protect against accidental...
Dust particles interacting with the proton beams have caused many thousand beam-loss events at CERN's Large Hadron Collider (LHC), some of which led to premature beam dumps and even magnet quenches. It has been hypothesized that dust particles on the vacuum chamber wall of the LHC are negatively charged due to electron clouds and can detach from the chamber wall by the electric field of the...
Elettra will be upgraded between 2025 and 2026 and the storage ring lattice will be totally different to enhance the emittance and improve the coherence of the machine.
The storage ring design requires a stiff support system to reduce the impact of vibrations on the electron orbits, a high thermal stability as well as low static deformations. The magnets support system must be easy to...
Elettra 2.0 is the name of the upgrade project of the existing Elettra Storage Ring (SR) and its ancillary systems. The project comprises also new beamlines (BLs) and the re-allocation of some of the currently operational ones.
Consequently, the “Experimental Hall” (EH) of Elettra, i.e. where the beamlines are installed, is another working area with activities that have started well before...
The LHC beam dump system has the task of safely and reliably disposing of the extracted beams from 450 GeV to 7 TeV. The present dump assembly consists of a multi-segment graphite core, which is contained in a duplex stainless steel vessel with titanium windows. To reduce the energy deposition density in the core and windows, the extracted beams are swept across the dump front face with...
Circular Electron-Positron Collider (CEPC) is a 100 km circumference double-ring Collider, the high luminosity lattice in CEPC TDR is half lower emittance compared with the lattice in CEPC CDR. The dynamic aperture is strongly sensitive to the magnet misalignments and field errors. We present the study of the error correction for the CEPC TDR lattice and the dynamic aperture tracking after...
We discuss the beam power loss related to the heating of the beam pipe walls of the FCC-ee interaction region. We analyse the excitation of trapped modes, which can accumulate electromagnetic energy and determine the locations of these modes. We study the unavoidable resistive-wall wake field, which is responsible for the direct beam pipe walls heating. We show the distribution of the heat...
The European X-ray Free Electron Laser (EuXFEL) is a user facility delivering soft and hard X-ray FEL radiation. It provides X-rays with high brilliance and intensities in the photon energy range of 0.5 keV to 25 keV. 2700 pulses at 10 Hz with femtosecond up to 4.5 MHz pulse repetition rate. The FEL radiation which is created by the Self Amplified Spontaneous Emission (SASE) process, whose...
The Interaction Regions (IR) of many colliders benefit from the application of leading-edge technologies to ensure the highest possible luminosity delivered to the experiments. Leading-edge low-beta focusing magnets and crab cavities to handle individual bunches are critically important to increase the instantaneous and integrated luminosity in future Colliders.
The High-Luminosity LHC...
The BEPCII has already realized the collision luminosity target of $1.0\times10^{33}cm^{-2}s^{-1}$ in April 2016. However, in the past six years of practical operation, the collision luminosity usually remains between $6.0\times10^{32}cm^{-2}s^{-1}$ and $8.5\times10^{32}cm^{-2}s^{-1}$. In the operation with high beam current, the BEPCⅡ displayed serious beam instabilities, which greatly limits...
The FCC-ee project takes a step forward towards the discovery of new physical phenomena beyond the frontier of the standard model, by aiming at unprecedented center of mass energies and luminosities in a double-ring lepton collider. In order to explore potential improvements to the current lattice design, this paper looks at the use of combined function magnets within the short straight...
Steady-state microbunching (SSMB) is envisioned to enable the generation of high-power coherent synchrotron radiation at an electron storage ring for wavelengths up to the extreme ultraviolet. The underlying mechanism has been shown to be viable in a proof-of-principle (PoP) experiment at the Metrology Light Source (MLS) in Berlin*.
An enhanced detection scheme allows systematic studies of...
A new collaboration between ESRF and DESY within the EURIZON project is aiming at building tools and concepts that can be used for the next generation light sources. The developed tools will be applied to the ESRF-EBS and the PETRA IV lattice models to validate concepts to improve the injection efficiency or the lifetime of storage rings.
In this project framework, the bounded Extremum...
During 2022, a dedicated study was undertaken at CERN, together with FCC Feasibility Study collaborators, aimed at proposing a robust configuration for the FCC-ee arc half cell. The proposed configuration takes into account integration aspects of the elements in the arc cross section, both for the booster and the collider, as well as aspects related to powering, cooling and ventilation,...
Sharing of emittances between transverse planes has potential benefits in storage ring light sources. The larger vertical emittance significantly increases the Touschek lifetime, while the smaller horizontal emittance helps to mitigate the loss in brightness at high photon energies due to the larger vertical beam size and divergence. A fully coupled beam is considered as an optional operation...
To improve the performance of beam orbit correction, it is necessary to perform beam-based alignment in modern storage ring light sources. For the High Energy Photon Source (HEPS), a 4th generation storage ring light source being built in China, because of the large number of BPMs in storage ring, it may take dozens of hours to complete the alignment with a conventional BBA algorithm. To...
The Fermilab Muon Campus, repurposed Tevatron-era Antiproton Source facilities, is currently the home to the g-2 and Mu2e muon experiments. Collecting data since 2017, the g-2 experiment is wrapping up a final run before the Muon Campus transitions to Mu2e operation. Currently in the commissioning process, the Mu2e experiment is expected to begin calibration and data collection in fiscal year...
The SuperKEKB accelerator, a collider consisting of 7 GeV electron and 4 GeV positron rings, is ongoing in order to supply a great number of interaction events of electrons and positrons to the Belle II detector which explores the new physics beyond the standard model.
The important milestone is to obtain integrated luminosity of 15 /ab in the next decade,
so that the luminosity should...
The PERLE (Powerful Energy Recovery Linac for Experiments) project relies on superconducting RF (SRF) cavities to reach its goals. The installation of coaxial couplers on the cutoff tubes of SRF cavities is foreseen for damping cavity’s Higher Order Modes (HOMs). The prototyping and fabrication of 3D-printed HOM couplers for the PERLE cavity have recently started in collaboration with JLab and...
The design of a muon collider complex requires to overcome challenges associated with muons short lifetime. To reach the expected luminosity for a multi TeV muon collider ring an interaction region with beta values of the order of a few millimetres is required. Resulting challenges are the development of a chromatic compensation section that is not degrading the physical and dynamical...
At LNL (Laboratori Nazionali di Legnaro), the vacuum system of ALPI (Acceleratore Lineare Per Ioni) accelerator includes about 40 pumping groups installed in the 90s. Obsolescence and rigidity of the used hardware and deficit of spare parts required a complete renovation of the system and relative controls. In 2022 we made the first steps of the system renovation with the development and...
Chromaticity up to the third order in the LHC has been well observed in the LHC’s first and second operational runs, with regular beam-based measurements performed during commissioning and machine development. In previous runs however, no higher-order chromaticity could be observed. In 2022, dedicated collimators setups meant optics measurements could benefit from an improved range of...
Rapid commissioning and automated start up procedures are crucial for many upcoming 4th generation storage ring light sources as their downtime demands are very challenging given their increased operational complexity. Detailed commissioning simulations as a tool of error analysis are not only used to guide the design process of new machines but also a prerequisite to implement an automated...
A two-day test of operation with Pb ion beams was carried out in the CERN Large Hadron Collider (LHC) in 2022, with the aim of gaining experience in view of the future high luminosity heavy-ion physics runs from 2023 onwards. The LHC experiments received the first Pb-Pb collisions at a record energy of 5.36 TeV centre-of-mass energy per colliding nucleon pair (beam energy 6.8 Z TeV). Bunch...
A Multipole Injection Kicker (MIK) has been successfully designed, constructed, installed and commissioned with beam in the MAX IV 1.5 GeV ring. This device allowed reaching injection efficiencies as high as those obtained with the previously used conventional dipole injection kicker scheme, while at the same time providing an order of magnitude reduction in the perturbations to the stored...
The proposed FCC-ee machine is a high-energy, high-intensity and high-precision lepton collider which will require to reduce as much as possible the differential motions of its two beams at the interaction points. In this prospect, the vibration impacts of the quadrupoles in the region close to the interaction point are investigated. Considering the z-pole optics design and its dedicated...
Superconducting undulators provide a possible means of broadening the range of wavelengths that can be covered by an XFEL facility by generating larger magnetic fields at shorter periods than can be achieved using permanent magnet undulators.
As part of ongoing prototyping work at STFC to develop a superconducting helical undulator with 13 mm period and 5 mm magnetic gap, a test cryostat has...
The High Energy Photon Source (HEPS) is a 4th generation synchrotron radiation source being built in China. An APPLE-Knot undulator with a new configuration is designed for the XCMD beamline of the HEPS. It is the first time to apply four-row APPLE-Knot undulator in storage ring based light sources. The main differences between the novel design and the conventional design of the APPLE-Knot...
GaAs cathode is a unique device generating a spin-polarized electron beam by photo-electron effect with a circularly polarized laser illumination. Negative Electron Affinity (NEA) surface which is artificially made has an essential role in spin polarization, but the NEA surface has limited vitality. In this study, we activated GaAs as NEA cathode by evaporating Cs, K, and Sb metal on its...
We are developing gamma-ray-induced positron annihilation spectroscopy (GiPAS) using ultra-short pulsed gamma rays at the UVSOR synchrotron facility in Japan. The gamma rays with the pulse width of picosecond range are generated by 90-degree inverse Compton scattering between a 750 MeV electron beam and an 800 nm laser. As the energy of the gamma rays is 6.6 MeV, gamma-ray irradiation produces...
A laser-driven storage ring is proposed to generate steady-state, nanometer-long electron bunches. A ring of this type can produce coherent EUV radiation with greatly enhanced power and photon flux, benefiting a wide range of scientific and industrial communities, including condensed matter physics and computer chip fabrication. The underlying mechanism is called generalized longitudinal...
One of the design requirements to reach a high luminosity in the Electron Ion Collider (EIC) is the collision of matched spot sizes of hadron and electron beams at the IP, with a horizontal to vertical emittance ratio of up to almost 20. However, the natural vertical emittance of electron beams in the Electron Storage Ring (ESR) in EIC is a few orders of magnitude smaller than the horizontal...
Iranian light source facility (ILSF) is a 4th generation synchrotron with a nominal horizontal emittance of 270 pm.rad. Storage ring magnet-girder support stability is essential for beam stability. The support system of storage ring girders is essential to achieve the accuracy of adjustment and vibration stability. After studying different girder support systems and considering the stability...
The Mu2e Experiment has stringent beam structure requirements; namely, its proton bunches with a time structure of 1.7µs in the Fermilab Delivery Ring. This beam structure will be delivered using the Fermilab 8-GeV Booster, the 8-GeV Recycler Ring, and the Delivery Ring. The 1.7-µs period of the Delivery Ring will generate the required beam structure by means of a third order resonant...
The longitudinal distribution of the electron beam in the electron storage ring of the Electron-Ion Collider will be modified by the machine impedance. The modified distribution, combined with crab cavities may have an impact on the quality of the hadron beam during the collision. In this paper, we will explore the possible impact on the hadron beam quality with strong-strong and...
Studies of the beam spectrum of the Large Hadron Collider (LHC) have revealed the existence of harmonics of the mains frequency (50~Hz), ranging from 50~Hz to 8~kHz, in the form of transverse dipolar excitations. The restart of the LHC operation in Run 3 was accompanied by substantial improvements in the beam instrumentation. In particular, the upgrade of the transverse damper’s observation...
Travelling wave (TW) SRF accelerating structures offer several advantages over the traditional standing wave structures: substantially lower Hpk/Eacc and lower Epk/Eacc, ratios of peak magnetic field and peak electric field to the accelerating gradient, respectively, together with substantially higher R/Q. In this paper we discuss how a linear collider Higgs factory HELEN can be built using...
Energy recovery of residual ions may be needed to increase the energy efficiency of Neutral Beam (NB) injectors for fusion plants as DEMO while a deflection-based system has been proposed. A compact beam energy recovery system, composed of 2 Farady Cups (FC) with holes for D0 passage, based on space charge effects, very effective to recover ions with low residual energy, has been proposed...
Inverse Compton scattering (ICS) is a method used for X-ray production that has been possible in recent years due to the rapid development of ultra-fast, short, and stable oscillators. In addition, the research and development of high Finesse Fabry-Perot Cavities to store high average power inside it. ThomX is a new generation of compact X-ray source which implements the ICS method. It will...
Run 4 will be the first operational run of the LHC with full deployment of the upgrades from the High Luminosity (HL-LHC) project planned for 2026-2028 (Long Shutdown 3). The commissioning goals for the first run were defined to approach steadily the design beam current, while already fulfilling significant luminosity goals. Despite extensive operational experience already gained, intensity...
Energy Recovery linear accelerator (ERL) light source facilities based on superconducting radiofrequency (SRF) are deemed of the most resplendent techniques in the future of accelerator physics. Running in a continuous waves mode with a high repetition rate for a long timescale, we discuss High order modes (HOMs) analysis in a two-pass two-way ERL scheme where acceleration and deceleration of...
The Spallation Neutron Source (SNS) recently took delivery of a third Radiofrequency Quadrupole (RFQ03) that will ultimately be installed on the front-end (FE) of the SNS Linac. The first RFQ (RFQ01) operated in the SNS FE for more than a decade before being replaced with the second RFQ (RFQ02). RFQ01 was relocated to the Beam Test Facility (BTF) where it operated for five more years. The...
FCC-ee performance is challenged by magnetic errors and imperfections. Magnetic design simulations predict a systematic quadrupolar component in the arc dipoles significantly impacting the machine optics. This paper studies the impact of this component in the beta-beating and explores potential mitigations.
The new EBS machine was commissioned in 2020 with a targeted nominal beam emittance of 139pm.rad in the horizontal plane. The radiated energy in the 70 insertion devices present from the restart was expected to change the equilibrium emittance. This paper presents the prevision and the measurements performed as a function of the total radiated power in the machine. The comparison shows that...
The concept of steady-state microbunching (SSMB) as a new scheme for the production of high power synchrotron radiation has been demonstrated at the Metrology Light Source in Berlin-Adlershof (MLS) [1].
At the MLS the same undulator section is used for the generation of the micro-structures onto the electron bunch as well as for the detection of the resulting coherent radiation from the...
The 7-GeV low-emittance electron beam is essential to be delivered to the SuperKEKB double-ring collider. One of the issues at the complicated beam transport between the linear accelerator and the High-Energy Ring (HER) is significant transverse emittance growth. In general, both incoherent and coherent synchrotron radiation effects play crucial roles in beam behavior. In this paper, we...
The layout of Elettra 2.0 preserves the useful length of the long straight sections so that all the existing insertion devices (IDs) could in principle be maintained in the upgraded machine. However, new high-performance beamlines are planned that will take advantage of the much lower electron beam emittance. Therefore new undulators are being designed and constructed for these beamlines....
The Future Circular Electron-Positron Collider (FCC-ee) aims to achieve unprecedented energies and luminosities. This can only be achieved using complex insertion region optics that set high challenges for commissioning and operating the machine. In the following we discuss some of the optics correction methods anticipated to be used to achieve the targets of the FCC-ee.
CNAO is one the six centers all around the world able to treat patients affected from cancer by proton and carbon
ions beams. Beams are produced by a synchrotron equipped with two sources. A third source has been recently
installed in order to produce new species that will be interesting both for clinical and R&D purposes.
A new low energy line has been designed, installed and...
The Electron-Ion Collider, to be constructed at Brookhaven National Laboratory, requires a large dynamic aperture (DA) of the electron storage ring (ESR) for stable operation of 10 beam sigma for the transverse aperture and 10 times the RMS momentum spread in the longitudinal plane. In particular for operations at the top energy of 18 GeV this has not been easy to achieve, and the DA has...
Initiated through the Physics Beyond Colliders (PBC) Study Group there is a strong interest from the scientific community to exploit the full intensity potential of the Super Proton Synchrotron (SPS) at CERN for Fixed Target physics experiments before the end of this decade. With the ECN3 cavern in the North Area (NA) identified as a suitable candidate location for a future high-intensity...
As preparation for the upcoming Diamond-II upgrade, provisions for timing-users (those who predominantly care about the timing characteristics of the synchrotron radiation) are being investigated. Although ‘Hybrid bunch’ modes are currently employed at Diamond, such operation presents challenges for Diamond-II that merit investigating alternative approaches. PPRE, one such approach, involves...
Ion instabilities are a major concern in diffraction-limited storage rings. ELEGANT offers a `strong-strong' model for ion simulations that describes both the beam and ions using multi-particles. To balance accuracy and computing resources, a simplified model using ILMATRIX and one IONEFFECTS element per turn is employed to study the ion effects of the Diamond-II storage ring. After...
The team at LANL continues efforts for the LANSCE Accelerator Modernization. This paper summarizes the progress in developing of the proposed concept of the modernization, and the major technical challenges that are expected in this concept. Separate subsystems are designed on the conceptual level, and the computer models for beam dynamics simulations are established and presented here. The...
In this paper, we present our thinking on how to keep the modulation laser and electrons phase-locked in a steady-state microbunching storage ring.
The Southern Advanced Photon Source (SAPS) is a 3.5 GeV, kilometer-scale, ultra-low emittance storage ring to be built next to the CSNS(China Spallation Neutron Source) in Guangdong Dongguan, China. A preliminary lattice design for SAPS storage ring with an emittance of 32 pm.rad has been proposed before. Now, the SAPS lattice is continuously under extensive design and optimization. In this...
Among the possible future lepton colliders under study, circular muon colliders have the largest potential of reaching center-of-mass energies of 10+ TeV. Being more massive than electrons and positrons, muons are much less affected by synchrotron radiation emission, but they suffer from the drawback of having a limited lifetime. As a consequence of their decay, intense secondary radiation...
The electron-ion collider will utilize a major portion of the existing RHIC rings for its hadron storage ring (HSR). This paper describes the lattice design of the HSR. Presently, RHIC consists of two rings, each of which contains 6 straight sections, and between those straights are arcs, each consisting of 11 FODO cells. The HSR uses 7 of the existing RHIC arcs which are unmodified, other...
We present the lattice design for the interaction region (IR) for the Electron-Ion Collider. We specify the requirements that the IR must meet, both for the hadron and electron beams themselves and for the collision products and radiation that must be transmitted through the magnet apertures. We align the hadron magnets downstream of the detector to pass the collision products while minimizing...
The Electron Ion Collider (EIC) Hadron Storage Ring (HSR) will utilize the Relativistic Heavy Ion Collider (RHIC) arcs and modified straight sections. Due to these modifications in the straight section of the on project electron Proton Ion Collider (ePIC) experiment, a new injection system needed to be built one arc downstream of the existing RHIC injection system. The new injection system...
The Metrology Light Source (MLS) is a 630 MeV electron storage ring as a synchrotron radiation source for the terahertz (THz) to the extreme UV spectral range. Its upgrade project MLS II is defined as a compact 0.8 GeV storage ring with multiple operation modes, which pursues lower emittance (<50 nm) in standard user mode and preserves
the strong capability of MLS to manipulate the momentum...
The Electron-Ion Collider (EIC) at Brookhaven National Laboratory will feature an electron storage ring that will circulate polarized beams with energies up to 18 GeV. Recently a study has been undertaken to extend the minimum energy from 6 GeV to 5 GeV. As the solenoid-based spin rotators around the interaction point require specific bending angles that depend on the energy range, this change...
The first year of Run 3 of the Large Hadron Collider (LHC) revealed significant changes in both linear and nonlinear optics errors with respect to Run 2. Several iterations of optics corrections were required to successfully bring the linear optics within operational tolerances. This paper presents the current status of optics corrections in the LHC and the challenges experienced in...
Diffraction-limited light sources have garnered significant interest -- yet the smaller equilibrium size of their electron bunches also reduces the beam-lifetime. One remedy is to vertically excite the electron beam, for instance using a Multi Bunch Feedback (MBF) system. Previous work has demonstrated that this approach can safely increase the vertical emittance, thus beam-lifetime. However,...
UVSOR, a low energy synchrotron light source, has been operational for about 40 years. It has been providing high brightness VUV radiation to users but also providing a research environment for light source technology developments. In this paper, first, we briefly review the history of the light source developments at UVSOR. Then, we describe a beamline BL1U, which is currently used for...
X-ray beamlines—essential components of all synchrotron light sources—transport emitted radiation from the stored electron beam to an experimental station. One may describe the linear optics of the beamline via an ABCD matrix computed using a ray-tracing code. Furthermore, one may then include diffraction effects and arbitrary wavefront structure by using that same information in a Linear...
Local coupling correction in Interaction Regions (IRs) and global coupling correction based on Base-Band Tune (BBQ) measurement have been performed routinely for RHIC operation. However, one still observes significant residual local coupling measured by beam position data. For the Electron-Ion Collider (EIC) project, betatron decoupling for the hadron beam needs to be improved to maintain a...
In the fourth-generation storage ring light sources, the dynamic acceptance is usually small related to the extremely strong nonlinearity inherent in the multi-bend achromat design, making it difficult to implement traditional off-axis local-bump injection. It was found that a double-frequency rf system can be used for longitudinal injection with the help of rf gymnastics. However, such...
To provide a more accurate and stable Radio-Frequency (RF) signal in conditioning and processing test progress, it is necessary to design an Low-Level Radio-Frequency (LLRF) control system which can provide high precision RF driving signal based on meeting the amplitude and phase stabilization requirement. Through Feed-Forward operation, accurate phase adjustment and amplitude adjustment are...
For a reliable determination of the single bunch stability threshold, the broadband impedance budget needs to be analyzed for all resistive and inductive contributions. The completely new design of the arc vacuum chamber of SLS 2.0 with respect to SLS - now with a reduced beam pipe diameter, and coated with layers of copper and NEG - requires special focus on the resistive wall impedance....
The Advanced Sources and Detectors project is building an advanced multi-pulse linear induction accelerator capable of generating a 1.4 kA electron beam at energies up to 24 MeV. The accelerator, named Scorpius after the brightest known x-ray source in the sky, will be unique in its use of solid-state pulsed power (SSPP) to generate the voltage pulse for the injector and accelerating gaps...
We’ll introduce a high precision active motion controller based on machine learning (ML) technology and electric piezo actuator. The controller will be used for srf cavity active resonance control, where a data-driven model for system motion dynamics will be developed first, and a model predictive controller (MPC) will be built accordingly. Simulation results as well as initial test results...
In 2022, the Large Hadron Collider started its third operational run. Following the three-year Long Shutdown 2, a careful re-commissioning of the machine protection system (MPS) took place. The initial hardware and beam commissioning period was followed by a 30-day-long intensity ramp-up, during which the number of circulating bunches was successively increased to 2460 bunches per beam. After...
The CLIC Beam Delivery System (BDS) transports the lepton beams from the exit of the Main Linac to the Interaction Point (IP). The Final Focus System (FFS) is the last part of the BDS and its role is to focus the beam to the required size at the IP and to cancel the chromaticity of the Final Doublet (FD). MAD-X and MAD-NG are simulation codes for beam dynamics and optics that are used for...
The proposed strong hadron cooler for the Electron-Ion Collider contains regions that transport beams with different energies. In this paper we present a possible magnet design for a broad range of beam energies.
The Shenzhen Innovation Light-source Facility (SILF) is a 4th generation diffraction limited storage ring project with an operating energy of 3 GeV, which is prosed by the Institute of Advanced Science Facilities, Shenzhen. For the storage ring, hybrid seven-bend achromat (H7BA) lattice is used in order to achieve a low electron beam emittance. There are longitudinal gradient bends (LGB),...
PERLE (Powerful Energy Recovery LINAC for Experiment) is a high-power Energy Recovery LINAC (ERL) facility with 20 mA beam current and beam energy from 250 MeV to 500 MeV featuring three passes through two cryomodules. It is a hub for validation of the ERL technology development towards future energy and intensity frontier machines. Design challenges of PERLE and its beam parameters make it a...
The diffraction-limited storage ring (DLSR) of the Southern Advanced Photon Source (SAPS) use a large number of ultra-high gradient quadrupoles and sextupoles, which leads to the tight tolerance of beam parameters to magnetic errors. We showed the results of the magnetic error effects in previous published article. On this foundation, the magnetic error corrections are finished, including the...
One of the design challenges of Superconducting undulators (SCUs) is the fulfilment of tight mechanical tolerances. Simulations show that to guarantee high quality of the emitted radiation local mechanical errors must be below a few tens of micrometres. Such requirements are at the limit of the most precise machines and techniques for mechanical manufacturing. In addition, once the SCU is...
The project of PolFEL free electron laser comprises 185 MeV cw-linac furnished with ASG electron gun and 4 Rossendorf-like cryomodules. Magnetic lattice has been designed applying alike air cooled quadrupole magnets. FODO quadrupoles in undulator section differ with trimmed coils. A variety of dipoles has been designed: 14 – degrees air and water cooled rectangular dipoles are used for low...
The Tapered undulator provides interesting possibilities for keeping the undulator in resonance with the electron beam along the length of the undulator. The U50-II [1,2] undulator at Laser and Insertion Device Application Laboratory of DAVV, India is a 1000mm length, 50mm period length undulator. The four heavy-duty precise lead screw attached to the mechanical girder allows its gap to be...
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. In the HEPS storage ring, a proportion of quadrupoles and sextupoles are equipped with trim coils for horizontal and vertical orbit correction. For these magnets, the main field and corrector fields may have non-ignorable impact on each other. We have carried out...
An 800 MHz, Radio Frequency Quadrupole (RFQ) was designed to accelerate the proton beam to 2 MeV energy at a distance shorter than one meter in KAHVE-Lab, Turkey. A half-length test module was previously produced to investigate the local manufacturability of this RFQ cavity. The manufactured test module was subjected to mechanical, vacuum and electromagnetic tests to adjust the pressure, EM...
Gaussian lasers with temporal or spatial chirp have been used in the manipulation of the electron beam in the high-gain harmonic generation or echo-enabled harmonic generation in free-electron lasers. This paper presents the Mathematica expressions of these lasers. This work is a first step for novel laser-electron manipulation technique in presence of temporal or spatial chirp.
Studies of third-order chromaticity in the LHC during its initial two runs have consistently demonstrated a substantial discrepancy between the expected Q''' at injection and that observed in beam-based measurements. In 2022 during Run 3, for the first time, studies of Q''' have been complemented by measurements of chromatic detuning, being the momentum-dependence of amplitude detuning, and...
Numerical simulations of the beam dynamics with the Coherent Wiggle Radiation (CWR) impedance for the preliminary EIC back-up ring cooler parameters and positive and negative momentum compaction are discussed in detail. We show the microwave instability threshold dependence on low-frequency CWR impedance in free space and for parallel plates. The numerically simulated results performed by the...
During loss maps performed with beam at injection energy in the LHC with the high octupole and chromaticity settings used for multi-train operation, large beam losses were observed at an injection protection device (TDIS). Although these losses did not present a threat to machine operation or protection, reducing them is of high importance to improve machine performance. Various strategies...
The largest current obstacle to SuperKEKB's luminosity goals is currently beam-related backgrounds occurring during accelerator operation. Thus, understanding the level of these backgrounds is of crucial importance for the future of the facility. In this work, we take advantage of the Belle II Electromagnetic Calorimeter's near-total coverage of the interaction region to create a spatial model...
Modernization of the NESTOR hard X-ray generator storage ring for switching to the operating frequency of the accelerator of 2.856 GHz requires corresponding changes in the design of the high-frequency system, and this, in turn, leads to the need to modernize the laser-optical system. The necessary calculations were carried out to determine the new characteristics of the pulsed laser, the...
To satisfy up-to-date technical requirements NSC KIPT hard X-ray source on the base of Compton scattering NESTOR should be modified. Essential modernization should be done in accelerator-injector, lattice of the storage ring, RF and optical systems.
In the paper the technical proposals of the facility modernizations and results of beam dynamic simulations in the modified facility are...
KEK has two light sources: Photon Factory (PF, 2.5 GeV) and Photon Factory Advanced Ring (PF-AR, 6.5 GeV). In 2017, the use of a new beam transport line (BT) of PF-AR was started, and the simultaneous top-up injection for both PF and PF-AR was realized. These days, there have been strong demands for the reduction of the operating cost of accelerators, and its importance is greater in PF-AR...
One of the most fundamental measurements since the Higgs boson discovery, is its Yukawa couplings. Such a measurement is only feasible, if the centre-of-mass (CM) energy spread of the e+e- collisions can be reduced from ~50 MeV to a level comparable to the Higgs boson’s natural width of ~4 MeV. To reach such desired collision energy spread and improve the CM energy resolution in...
The system in place for remote alignment of the girders, which carry the storage ring elements of the PETRA III light source in the Max von Laue experimental hall, were never used to perform re-alignments after the initial installation of the storage ring in 2009. Since the planned upgrade, PETRA IV, can benefit from the fine control of the girder position to achieve the design beam...
Ultra-high brightness and ultra-low emittance electron beams can great enhance the radiation power in light sources, but the electron beams are prone to nonlinear effects in the velocity compression, which leads to the asymmetry of the beam. In this paper, a multi-objective optimization method based on NSGA-III is proposed to achieve a good symmetry in the C-band photocathode injector with an...
In beamline design, there are many floating parameters that need to be tuned; manual optimization is time-consuming and laborious work, and it is also difficult to obtain well optimized results. Moreover, there are always several objectives that need to be considered and optimized at the same time, making the problem more complicated. For example, asking for both the flux and energy to be as...
Transverse multibunch instabilities are of significant interest in accelerators with strong wakes and large bunch trains. In such cases, wakes that do not damp sufficiently from bunch to bunch can drive instability along the entire bunch train. Simulations are useful for understanding such instabilities, but the multiscale nature of the system and numerical noise can make results uncertain. A...
Utilizing short RF pulses ($\sim$9 ns) with Dielectric Disk Accelerators (DDA) is a way to improve the energy efficiency of a linear accelerator and decrease the required footprint while still achieving large energies. A DDA is an accelerating structure that utilizes dielectric disks to improve the shunt impedance while still achieving large accelerating gradients. A single cell clamped DDA...
A method to reconstruct the momentum distribution of the injected muon beam in the Muon g-2 Storage Ring at Fermilab has been developed, which is based on beam profile measurements from the Muon g-2 straw tracking detectors as input. Extending a spectrometric perspective to the muons injected into the Muon g-2 storage ring, a direct transformation of the beam radial coordinates when the...
Muons circulating in a muon collider decay and generate neutrinos within a small solid angle, which reach the earth’s surface. One of the challenges of a high energy muon collider is to ensure that showers created by such neutrinos interacting close to the earth’s surface result in very low radiation levels. The neutrino radiation cone from a muon beam without divergence is estimated through a...
The Nuclotron-based Ion Collider fAcility (NICA) is under construction at JINR. The NICA project goal is to provide colliding beams for studies of hot and dense strongly interacting baryonic matter and spin physics. The NICA Collider includes two rings with 503 m circumference each and the injection complex. For the heavy ion mode, the injection complex consists of following accelerators: 3.2...
To maintain polarization in a polarized proton collider, it is important to know the spin tune of the polarized proton beam, which is defined as the number of full spin precessions per revolution. A nine-magnet spin flipper has demonstrated high spin-flip efficiency in the presence
of two Siberian snakes. The spin flipper drives a spin resonance with a given frequency (or tune) and strength....
The 18 GeV Electron Storage Ring (ESR) lattice of the Electron-Ion Collider (EIC) showed various undesirable effects in nonlinear Monte Carlo tracking, including a vertical core emittance exceeding radiation-integral predictions and a low asymptotic polarization. These problems were resolved in a newer lattice where dispersion in the solenoidal spin rotators was set to zero. Here we identify...
As an energy frontier machine, the proposed Super Proton-Proton Collider (SPPC) will have the capability to explore a much larger region of new physics models with center of energy around 125 TeV and circumference 100 km.
The nonlinearity optimization of the SPPC collider ring lattice is essential to get a high peak luminosity and lifetime of the beams. In this paper, a collider ring lattice...
The booster ring of High Energy Photon Source is responsible for ramping the beam energy from 500 MeV to 6 GeV. Six 5-cell copper cavities of PETRA-type were chosen to provide a total accelerating voltage of 8 MV. To fulfill the specific requirements of the HEPS booster, several modifications were made on the original design from Research Instruments (RI). Six cavities manufactured by RI...
Taiwan Photon Source (TPS) had delivered the first synchrotron light on the last day of 2014. Installation of 16 beamlines of the first and second phases of TPS beamline project was completed. The third phase project also had been launched in 2021. To confront the situation that the experimental hall is more compact, we per-formed Computational Fluid Dynamic (CFD) simulation to analyse the...
We have developed numerical method to calculate temporal structure of synchrotron radiation in arbitrary magnetic field. Using this method, spectral phase of synchrotron radiation can be calculated, which is important in the reconstruction of temporal structure of radiation. It is also interesting that it reflects the symmetric property of magnetic field from which radiation is generated....
The electron storage ring DELTA which is operated by TU Dortmund University can be run at a reduced beam energy down to 500 MeV instead of 1.5 GeV. If a single bunch at low energy is stored, the bunch charge threshold for the emission of THz bursts is exceeded. Using a fast Schottky-barrier detector, coherent synchrotron radiation bursts of THz radiation were detected. Turn-by-turn data of the...
SuperKEKB suffers from sudden beam loss(SBL) during operation. It causes collimator damage, QCS quench and large beam background to the Bell-II detector. Beam aborts triggered by SBL hinder us from storing large beam current. Since cause of SLB is unclear, we launched an effort to investigate it and consider measures to be taken. In this paper, we discuss phenomena of SBL and various...
In this study we investigate the advantages and challenges of applying the two frequency crab cavity short pulse scheme to multi-bend achromat (MBA) lattice based fourth generation synchrotron light sources. Using the Advanced Photon Source Upgrade (APS-U) lattice as a concrete example, we show that short pulses with duration of 1~10 ps (FWHM) can be generated with modest deflecting voltages....
The ESRF-EBS is the first 4th generation source making use of the Hybrid Multi-Bend Achromat (HMBA) lattice cell, reaching an equilibrium horizontal emittance of 140 pm.rad in user mode (insertion devices (ID) gaps open). An off-energy operation was proposed to further reduce the equilibrium emittance by about 20 pm.rad. A first proposal rematched the HMBA optics at an energy deviation of -1\%...
The application of HTS coils as a matching device and a large-aperture L-band linac make it possible to transport a substantial part of positrons generated in a positron production target through a capture linac. It raises a question of how to manage their large phase space to provide bunches matched to the damping ring acceptance. This paper presents the beam dynamics studies of the FCC-ee...
The strong intra beam scattering effect and the increase in horizontal emittance become common issues for next-generation ultra-low emittance storage rings. The round beam can be an effective method to solve these problems. Moreover, the produced round synchrotron radiation is suitable for optical matching. The on-resonance tune is an easier method to achieve round beam. In this paper,...
The European Synchrotron Radiation Facility - Ex-tremely Brilliant Source (ESRF-EBS) is a facility upgrade allowing its scientific users to take advantage of the first high-energy 4th generation storage ring light source. In December 2018, after 30 years of operation, the beam stopped for a 12-month shutdown to dismantle the old storage ring and to install the new X-ray source. On 25th August...
During the third run period of the CERN Large Hadron Collider (LHC), as well as for the future High-Luminosity LHC era, luminosity levelling by beta* is a key technique to control the pile-up in the high-luminosity experiments ATLAS and CMS while maintaining Landau damping through the head-on beam-beam interaction. This implies changing the machine optics in the interaction regions while...
A non-negligible risk of magnet quenches occurring due to the reduced cleaning performance of the original LHC collimation system with lead ion beams was expected at an energy of 6.8 Z TeV beams. Crystal collimation has therefore been integrated into the HL-LHC upgrade baseline to overcome present limitations. The upgrade scope involves the installation of 4 new crystal primary collimators....
In addition to the physics program with proton beams, the Large Hadron Collider (LHC) also provides collisions of fully-stripped Pb beams for about one month per year. When colliding Pb-Pb nuclei, electromagnetic interactions are the dominating processes because of the intense Coulomb field produced by the ions. These 'ultra-peripheral' interactions give rise to special losses in the machine...
In this paper, we present the possible use of laser Compton back scattering (CBS) to adjust and tune the bunch intensity. In the future circular electron-positron collider “FCC-ee”, the intensity of the colliding bunches should be tightly controlled, with a maximum charge imbalance between collision partner bunches of less than 3–5%. The control of such tolerance is necessary due to the strong...
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34cm^{-2}s^{-1} in the center mass energy range of 20-140 GeV. Preliminary beam-beam simulations resulted in an optimum working point of (.08, .06) in the Electron Storage Ring (ESR). However, during the...
MINERVA entails the first phase of the MYRRHA programme, which aims at driving a nuclear reactor with a high-power proton accelerator, commonly referred to as an Accelerator Driven System(ADS). The purpose of MINERVA is to demonstrate the reliability requirements that are needed for a stable ADS, by the realization of a 100 MeV, 4mA proton beam.
In order to transport the proton beam with...
The Swiss Light Source (SLS) will shut down in October 2023, entering the dark time period for installation of the upgraded SLS 2.0 synchrotron. The commissioning of the new electron storage ring is planned for early 2025. The upgraded storage ring features a lattice based on modern 7-bend achromats with lower momentum compaction factor, NEG coated vacuum pipes of smaller aperture and an...
The prototyping accelerator based on laser-plasma technology (PALLAS) project aims to build a laser-plasma injector accelerator (LPI) test facility to deliver within a few years electron beams of 150-250 MeV, >30 pC, <1 mm.mrad emittance beam at 10 Hz with control and stability comparable with RF accelerator. The project is, among others, built in the framework of the technical preparatory...
A facility for a muon collider brings the big advantages of a compact lepton collider and a collision energy up to several TeV, well above the energy reach of conventional electron circular accelerators.
However, the short lifetime of muons drives the design of the accelerator complex and collider, which makes this complex unique. A high muon survival rate and luminosity requires an extremely...
The observation of the Higgs boson by the LHC (2012), and the direct observation of gravitational waves (GW) from a collapsing binary systems by LIGO (2016) marked the successful end of long-standing efforts, and hopefully the dawn of a new era where both fields, Particle Accelerators (PA) and GW Physics, may benefit from knowledge/technologies developed by the other party. CERN recently...
NSLS-II is a 3 GeV third generation synchrotron light source at BNL. The storage ring was commissioned in 2014 and began its routine operations in the December of the same year. Since then, we have progressed steadily upwards in beam current and reached 500 mA in five years while increasing new insertion devices. Along this path, we report various challenges and the improvements to reach high current.
The Physics Beyond Colliders (PBC) studies at CERN address the possibility to utilise protons in the Large Hadron Collider (LHC) for a fixed-target program beyond the colliding-beam physics. As part of PBC, a double-crystal test stand is considered for installation in the LHC off-momentum collimation Insertion Region (IR) 3. In this PBC experiment, a first silicon crystal deflects beam-halo...
The community studying facilities to measure a possible Electric Dipole Moment of a charged particle (cpEDM) in a storage ring agreed that a Prototype Storage-Ring (PSR) is required as intermediate step to address critical questions, gain experience and rule out showstoppers. In what follows, a new lattice proposal of the PSR with a periodicity five is described and spin tracking simulations...
Undulators containing magnetized rare-earth helices can provide a significantly higher oscillatory electron velocity than the widely used planar Halbach undulators. Using Wire Electrical Discharge Machining (WEDM) and combining planar tool with rotary work piece motion, it is possible to manufacture NdFeB helices with a period of 1 mm or less with high accuracy. In this work, we describe the...
The Synchrotron Light Source PETRA III is one of the core facilities at DESY offering each year more than 2000 users unique opportunities for experiments with hard X-rays of a very high brilliance. The light source is operated mainly in two operation modes with 480 and 40 bunches at a beam energy of 6 GeV. The availability and failure statistics is reviewed for the year 2022 in comparison with...
Research and development of an accelerator-based THz source prototype for pump-probe experiments at the European XFEL are ongoing at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). Proof-of-principle experiments have been performed to generate a high-gain THz Free-electron Laser (FEL) based on the Self-Amplified Spontaneous Emission scheme. The FEL radiation pulses with a central...
A series of power outages during setup for RHIC Run 23 damaged two of the four helical dipole modules that comprised one of the full Siberian Snakes in RHIC’s Blue ring. The remaining two helical dipoles were reconfigured as a “partial” snake, one which rotates the spin by an angle less than 180 degrees. This partial snake configuration has a rotation angle and axis which both deviate from...
Positron beams would provide a new and meaningful probe for the experimental program at the Thomas Jefferson National Accelerator Facility (JLab). The JLab Positron Working Group, formed in 2018 and now with over 250 members from 75 institutions, continues to develop an experimental program with high duty-cycle positron beams including but not limited to future hadronic physics and dark...
The Large Hadron Collider (LHC) is equipped with a betatron halo collimation system designed to prevent magnet quenches during periods of reduced beam lifetime. Protons subject to single diffractive scattering in collimators can nevertheless leak into the adjacent dispersion suppressors (DS). In view of the future high-luminosity (HL) upgrade of the LHC, a better understanding of the quench...
To explore the beyond standard model of elementary physics, we proceed a new fundamental physics experiment, J-PARC muon g-2/EDM experiment. To realize very precise measurement of the muon spin precession frequency in the level of sub-ppm, a relativistic energy of muon beam is injected into a precisely adjusted storage magnet of sub-ppm uniformity by applying medical MRI magnet technologies....
The Korea 4th Generation Storage Ring(Korea-4GSR) project has been launched in 2022. The Korea 4GSR aims to generate the ultra-low emittance beam with the beam current of 400 mA and the beam energy of 4 GeV. In order to accelerate and store the beam to desired parameter, the Storage Ring RF(SRRF) is composed of 10 or more RF Stations and each RF Station includes LLRF(Low Level RF), HPRF(High...
Hefei Advance Light Facility (HALF) is a 2.2 GeV diffraction-limited storage ring, which is developed by National Synchrotron Radiation Laboratory in China. It has 20 long straight sections and 20 middle straight sections. All the experimental stations in the first stage will employ undulator as the light source. In this paper, we introduce the preliminary design of insertion devices of HALF,...
In the FCC-ee study, it is proposed that electron and positron beams circulate at high current and high energy in a 92-km circumference ring. The present operational scenario foresees a first running step at an energy of 45.6 GeV and around 1.4 A current, which would generate copious amounts of synchrotron radiation (SR) power and flux. To guarantee a quick decrease of the photon desorption...
The Steady-State Microbunching (SSMB) mechanism, which combines the benefits of high repetition rate of a storage ring and coherent radiation, has the potential to produce high average power short wavelength light. In order to generate kilowatt level radiation, the electron injector should have the ability to provide a 1 A average current, 100 ns long DC beam, with the requirements of small...
Rapid cycling synchrotron (p-RCS) is the first synchrotron of the accelerator chain in the proposed Super Proton-Proton collider (SPPC) project. It will provide high-energy and high-power beams for the injection to the downstream accelerators for SPPC collision with the required beam characteristics such as bunch spacing, bunch population and emittance, but also serve independent application...
In this paper we will show the injection philosophy and the design of timing and filling scheme for high luminosity CEPC scheme under different energy modes. It is found that the RF frequency choice in CDR cannot meet the injection requirements for the bunch number at Z pole. A modified scheme was proposed to support the design luminosity,which basically meets our current design requirements and...
Since the upgrade and renovation of the East Experimental Area at CERN during Long Shutdown 2 (LS2: 2019 - 2021), demand has increased for slowly extracted beam from the CERN Proton Synchrotron (PS). The East Area is a multi-user facility carrying out a diverse experimental physics programme. It requires a wide range of slowly extracted beams to be delivered by the PS. This contribution...
The potential future Soft X-ray (SXL) FEL beamline at the linear accelerator at MAX IV will require a series of undulators with distinct properties: It must be cost-effective and compact. Furthermore, it needs to have a small and round magnetic gap and provide elliptically polarized light under full polarization control. This undulator of a compact APPLE X type is currently being prototyped...
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The construction of HEPS started in mid-2019. Later, to deal with challenges emerging from the technical and engineering designs, the HEPS accelerator physics design was modified and had been finalized in 2020. Afterwards, studies on related physics issues were updated...
We report on progress developing the Energy and RF ramp for the EIC’s Rapid Cycling Synchrotron (RCS). The development of the RF voltage and phase ramp from injection energy at 400 MeV to 5, 10 and 18 GeV extraction energy requires control of the bunch’s longitudinal aspect ratio to avoid both collective instabilities, RF bucket height and width as well as lattice dynamic aperture limits....
The Hefei Advanced Light Facility (HALF) is a soft X-ray and VUV diffraction-limited storage ring to be built in the Hefei city of China. This paper reports the recent progress on the physics design of the HALF storage ring, including lattice modification and optimization, error and insertion device effects, collective effects, injection scheme and collimation.
A new ISOL rare isotope beam production facility, ARIEL, is being commissioned to triple the availability of radioactive ion beams for the ISAC experimental facilities at TRIUMF. Part of ARIEL is the new CANREB charge breeding facility that includes RFQ cooler, EBIS and Nier separator, and a high-resolution mass separator system (HRS). The HRS is designed to achieve a resolving power of 20,000...
In the Large Hadron Collider (LHC), corrections of local Interaction Region (IR) linear coupling are of importance to control beam sizes at Interaction Points (IPs) and hence the luminosity performance, as well as to prevent a significant impact on the beam dynamics. During the LHC Run 3, the skew quadrupole corrector magnets used on either side of IPs are expected to exceed their radiation...
The LHC beam dump system was developed to safely and reliably dispose of the LHC beams at the end of physics fills or in case of emergency aborts. The beams are extracted by means of kicker magnets, deflecting the beams horizontally, and septa, which provide a vertical kick. The system must be able to cope with rare failure scenarios, such as an asynchronous beam dump, where the rise time of...
The user service mode of ESRF started in August 2020 after the installation of the new EBS machine, replacing the original ESRF DBA storage ring. All the insertion devices (IDs) were stored and re-installed to be available from day-1 of the accelerator commissioning. A major concern was, and still is, to preserve them as much as possible from demagnetization, both low gap in-vacuum devices and...
We describe optics designs of the key components of proton and electron Recirculating Linear Accelerators (RLAs). They are presented in the context of a high-power hadron accelerator being considered at ORNL and a CEBAF electron energy doubling study, FFA@CEBAF, being developed at Jefferson Lab. Both concepts rely on the Fixed-Field Alternating gradient (FFA) arc optics designs where multiple...
The muon linear accelerator is under development at J-PARC for precise measurement of muon anomalous magnetic moment and electric dipole moment. Four 2592 MHz disk-loaded structures (DLSs) operating in the TM01-2pi/3 mode take charge of the acceleration of high-velocity muon from 70% to 94% of the speed of light. They have disk-iris apertures tapered to generate a quasi-constant gradient of 20...
An in-vacuum undulator is important for synchrotron radiation. An in-vacuum undulator with a permanent-magnet is used by the Taiwan Photon Source (TPS) in the National Synchrotron Radiation Research Center (NSRRC). Before installation in the storage ring, the magnetic field of the undulator is measured at the oper-ational gaps. The magnetic-field for an in-vacuum un-dulator is measured using a...
The user community of the Angle-Resolved Photoemission Spectroscopy (ARPES) beamline in Diamond Light Source (DLS) is strongly interested to use the lower photon energies down to 10 eV compared to the current 18 eV in both Diamond and the future 3.5 GeV machine Diamond-II. The high level of the heat load on the first optic as well as the undesired higher harmonics contamination are two major...
In recent years, there has been an increasing interest for experiments in the LHC complex that aim to push the frontiers of Physics, in locations that do not interfere with the normal operation of the machine while guaranteeing an acceptable signal-to-background ratio. This is the case with the Forward Search Experiment (FASER), which was approved in 2018, followed by the approval of the...
The European Spallation Source (ESS) project currently enters the final stage of installation. Since 2017, a group of engineers and technicians from The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Science (IFJ PAN) are involved in the project. The contribution to the project can be divided into three main tasks: Radio Frequency Distribution System (RFDS), RF (Radio...
Shanghai Laser Electron Gamma Source (SLEGS) beamline, based on laser Compton scattering (LCS), as one of beamlines of Shanghai Synchrotron Radiation Facility (SSRF) in phase II project, has been construct-ed and started test commissioning from July 2021. The results of the commissioning already show a steady experimental proof that SLEGS can produce gamma rays with adjustable maximum energy...
The design of Southern Advanced Photon Source (SAPS), which is a 3.5 GeV storage ring based light source, has been actively updated in the past two years. In addition, many relevant research activities such as the development of an electron source, high gradient accelerating structures, RF cavities and power supplies for fast injection kickers have already been started. The updated overall...
The Future Circular Collider (FCC) study comprises two accelerators, namely a high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh). Both rings share the same tunnel infrastructure, analogous to LEP and LHC. We present the current design status of FCC-hh, updated from the Conceptual Design Report (CDR) and with recent developments including the new designs of the...
The Taiwan Photon Source (TPS) experimental facility has experienced vibration interference at approximately 16.8 Hz during experiments at the end station of the TPS 23A beamline, which was traced back to the air handling units (AHUs) located on the second floor of the outer ring area of TPS. The vibration of the AHUs not only affects the TPS beamline 23A end station but also all experimental...
The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source being built in China. Basic accelerator physical design and vacuum design have been completed. Interactions between the accelerated particles and the residual-gas molecules will lead to a reduction in the beam lifetime. The residual gas lifetime includes contributions from elastic gas scattering and...
10Hz horizontal orbit oscillation due to helium flow was observed in the routine operation of the Relativistic Heavy Ion Collider (RHIC). Without compensation by 10Hz orbit feedback, this will cause sizeable luminosity variation and reduce the beam lifetime during physics stores. In this article, we revisit the effects of this beam oscillation with weak-strong beam-beam simulation and dynamic...
The Diamond-II storage ring will utilise normal conducting main cavities and a passive superconducting harmonic cavity in its RF system. To evaluate the effects of bunch lengthening and lifetime gain from the harmonic cavity for different filling patterns, transient beam loading effects need to be studied. When simulating these effects with ELEGANT, RF feedback for the main cavities must be...
The CERN Super Proton Synchrotron (SPS) aims at providing stable proton spills of several seconds to the North Area (NA) fixed target experiments via third-integer resonant slow extraction. However, low-frequency power converter ripple (primarily at 50 and 100 Hz) and high-frequency structures (mainly at harmonics of the revolution frequency) modulate the extracted intensity, which can...
The hybrid multi bend (HMBA) lattice has been introduced to the accelerator community with the ESRF-EBS storage ring. Scaling an HMBA storage ring (SR) to different number of cells or cell length may lead to loss of performances, in terms of dynamic aperture (DA), momentum acceptance (MA) and natural horizontal emittance of the resulting SR. In this article we present several (non-exhaustive)...
The Siam Photon Source, a synchrotron light source in Thailand, has undergone multiple improvements in recent years, including the installation of up to four insertion devices in the storage ring. The machine has operated at maximum capacity for a significant period of time. This study presents a statistical analysis of the machine's operation over the past seven years, including the number of...
The feasibility of performing sextupole injection at TPS (Taiwan Photon Source) storage ring has been demonstrated in November 2021 with 300 mA stored electron beam. In order to carry out the experiment, a sextupole and its associated pulser were fabricated according to the specifications required. The sextupole was installed during a short break in September 2021 by making use of a ceramic...
China Spallation Neutron Source (CSNS) is a high density complex with a high repetion rate of 25Hz. The Rapid Cycling Synchrotron is the key part of the CSNS. By adopting the sextupoles with pulsed beam power system, CSNS has been operating steadily at 140kW. The CSNSII is aim to deliever above 500kW with the upgrations of many aspects of the accelerator. The sextupoles upgration is very...
The Proton Storage Ring (PSR) of LANSCE compresses the pulse of a linac-produced beam by a factor of more than 2000 into an ultra-short high intensity beam, making the Lujan Center a leading facilities in the delivery of instantaneous beam power. This short-pulse feature allows a variety of experiments from neutron science to fundamental nuclear physics. Further shortening the beam pulse by...
Short pulsed proton beams of 8 ns has been extracted from FFAG accelerator in KURNS. Bunch rotation after adiabatic debunching was used at highest energy orbit.
A new in-vacuum undulator (IVU) with varying gap width is being developed for the new X-Ray source, PETRA IV at DESY. Its electromagnetic properties need to be investigated. These include, especially, the losses in the flexible taper transitions between the beam pipes and in the magnet array, as well as the impact of the IVU's impedance on beam stability. To assess the impedance of the...
The AAC community proposed linear collider concepts with energies extending to 15 TeV center-of-mass and luminosities up to 50E34 cm^-2 s^-1 as part of the Snowmass process. The beam power required to reach these energies and luminosities is prohibitive. We discuss the results of initial investigations of strategies to increase luminosity per beam power, a key figure-of-merit for linear...
We propose a computationally efficient algorithm to calculate a single statistical realization of partially coherent synchrotron radiation fields at a given frequency. The proposed algorithm relies on a method for simulating Gaussian random fields. We cross-checked the algorithm’s consistency with other well-established approaches, and, in addition, we show its advantage in terms of...
The strong field of the experimental solenoid around the interaction point has a considerable effect on the beam optics. Moreover, if the beams traverse the solenoid at an angle, as it is typically the case in a collider, the solenoid will also affect the closed orbit within and beyond the solenoid. Simulating these effects is not trivial. In the following we outline different philosophies of...
The High Energy Photon Source (HEPS), is an ultra-low emittance storage ring (USR) light source beingto be built in Beijing, China. Due to the characteristics of the compact 7BA structure with strong focusing, beam accumulation in an USR is expected to be very challenging. Our simulations confirmed the difficulty in the HEPS storage ring. This paper introduces the preparations made for the...
The High Energy Photon Source (HEPS) is a 6 GeV, 1.3 km storage ring light source being built in Beijing, China. To get an ultralow emittance, high-gradient quadrupoles, combined-function magnets and longitudinal gradient dipoles (BLG) are adopted in the design of the storage ring. The impact of fringe field effects is of interest. To this end, several methods based on one-dimensional and...
The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34cm^{-2}s^{-1} in the center mass energy range of 20-140 GeV. To compensate the geometric luminosity loss due to a large crossing angle in the EIC, crab cavities are to be installed on both sides of...
During about one month in every operational year, the Large Hadron Collider (LHC) works as a heavy-ion collider. Four one-month Pb-Pb runs have been executed so far, as well as two p-Pb runs. The LHC heavy-ion programme is scheduled to continue in the future, featuring increased luminosity and beam energy. Beam losses caused by ions fragmenting in the collision process risk introducing...
Fixed Field Accelerators are a candidate for future hadron cancer therapy facilities as their high repetition rate and large energy acceptance enables novel treatment modalities such as high dose rate FLASH. However, conventional dose delivery mechanisms are still necessary, requiring continuous beam delivery over 1--30s. This work is the first study of slow extraction from a scaling Fixed...
The periodic orbit change caused by the temperature fluctuation of the cooling water at the SAGA-LS storage ring was suppressed by the slow orbit feedback correction system using newly equipped extra-windings on 8 steering magnets.
In recent years, the amplitude growth of temperature fluctuation of the cooling water caused maximally 40 micrometer periodic orbit change at the SAGA-LS storage...
The extraction inefficiency of the slow extraction process induces radioactivity in the area surrounding the electrostatic septum. Studies at the CERN Proton Synchrotron (PS) are investigating beam loss reduction techniques to improve the efficiency of the beams provided to the experiments of the East Area. Powering octupoles distorts the transverse phase-space of the extracted beam which can...
The beam abort system for the current Swiss Light Source (SLS) is based on inverting the RF phase to decelerate the stored beam. The losses are localised at longitudinal positions where the dispersive orbit encounters the machine aperture. For the SLS, these losses mainly occur at the septum and in the arcs. For the SLS 2.0* with its multi-bend-achromat lattice and thus much lower dispersion...
The Swiss Light Source SLS will have a 15 months long shutdown starting in October 2023 in order to install the new storage ring SLS 2.0. While the procurement of large series of components like magnets, power supplies, RF, vacuum chambers, … has started, the design of more specific components like the thin septum, undulators or collimators, is close to completion. The main difficulties and...
There has been a recent explosion of interest for a Muon Collider (MuC) as evident by the number of journal publications, related workshops and white papers submitted for the 2021 Snowmass Study. In light of this strong interest and in order to provide input for Snowmass, a MuC Forum has created in 2020. It facilitated a strong bond and exchange of new ideas between the particle physics...
The synchrotron SOLEIL is both a 2.75 GeV third-generation synchrotron light source and a research laboratory at the forefront of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. We present the performance of the accelerators delivering extremely stable photon beams to 29 beamlines....
The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source, which started construction in 2019. The sextupole and octupole magnets in the storage ring of HEPS are divided into several groups, and each group of magnets shares one power supply. In the lattice design, magnets in the same group are identical, but the real magnets have errors, which violate the...
At DELTA, a 1.5-GeV synchrotron radiation source at TU Dortmund University, ultrashort radiation pulses are generated using CHG (coherent harmonic generation), where the interaction with laser pulses in an undulator (modulator) causes a periodic electron energy modulation within a 50-fs slice of a 2000-times longer electron bunch. A dispersive chicane creates a density modulation giving rise...
The possibility of spin control for dEDM experiment can be done by setting Wien Filters in straight section, which ensure that the particles spin retains mean direction in accordance with «Quasi-Frozen Spin» mode. However, the spin of different particles, due to their different motion in 3D space, in any case rotates with slightly different frequencies around the invariant axis, which one...
The high precision measurement of the centre-of-mass energy in the Future Circular Collider e+e- (FCC-ee) at Z and W energies can be realized through resonant spin depolarization utilizing transversely polarized beams. This requires a guaranteed sufficiently-high spin polarization in the presence of lattice imperfections. Investigations of the impact of misalignments on the equilibrium...
We describe methods for measuring the three-dimensional stable spin vector for RHIC stores at two locations in the ring, namely the proton-Carbon (pC) polarimeters and the interaction point at the STAR detector. Both the pC and STAR local polarimetry can only measure the two transverse components of the stable spin direction. Measuring the full spin vector requires making a local spin...
The Drift Tube Linac (DTL) for the ESS Linac will accelerate H+ beams of up to 62.5 mA peak current from 3.62 to 90 MeV. The structure consists of five cavities. The first cavity (DTL1, 21 MeV) has been commissioned with beam in summer 2022. DTL2, 3 and 4 are installed in the tunnel since the end of 2022, ready for the conditioning and commissioning starting in 2023. DTL5 is under assembly and...
In the context of the FCC IS European study, which investigates the feasibility of a 100 km circular $e^{+}e^{-}$ collider for the future high energy physics research, we present the status of the High Energy Booster (HEB) ring. The HEB will be located in the same tunnel as the collider and should have the same circumference. The main difference is to have a bypass near the experiments to...
High Energy Photon Source (HEPS), a 6 GeV diffraction-limited synchrotron light source, is currently under construction in Beijing. The double-frequency RF system is being developed to deliver 6 MV of RF voltage and 850 kW of beam power with an active third harmonic system. The prototypes of the higher-order-mode damped 166.6 MHz quarter-wave superconducting cavities, as well as the 499.8 MHz...
Building new experimental facilities to house experiments is an expensive and time-consuming activity. Although usually less expensive, repurposing old experimental facilities to accommodate new ones has its own set of challenges with regard to obsolete equipment, adequacy of electrical power, radioactive shielding and cooling capacity. At Los Alamos National Laboratory (LANL), one such...
In this work, we examine the beam correction requirements for the FFA@CEBAF energy upgrade. Both hardware and software diagnostic and corrector components are under investigation; in particular the relationship between hardware and software optimization will be developed. To generate a representative sample of errors---from the machine lattice and other beam properties---we construct a Markov...
The International Linear Collider is a proposed electron-positron linear collider, where the positron beam is generated by undulator radiation hitting a target. The resulting, highly divergent positron beam requires immediate optical matching to improve the luminosity and ensure the success of the intended collision experiments. Here, optical matching refers to the process of capturing...
In recent years, high-gradient, symmetric focusing with active plasma lenses has regained significant interest due to its potential advantages in compactness and beam dynamics compared to conventional focusing elements. A promising application could be optical matching of highly divergent positrons from the undulator-based ILC positron source into the downstream accelerating structures to...
The ALS-U project is an upgrade to the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory that aims to deliver diffraction-limited x-ray beams with an increased beam brightness of two orders of magnitude for soft x-rays compared to the current ALS facility. A nine-bend achromat lattice Storage Ring (SR) and a three-bend achromat Accumulator Ring (AR) will be installed...
Two High Luminosity Large Hadron Collider (LHC) type crab-cavities have been installed in the CERN SPS for testing
purposes. A first partially successful attempt to characterize the skew-sextupolar component of the radio frequency field of the crab-cavity
by means of beam-based techniques has been carried out in 2018.
The large orbit distortion produced by the crab cavity dipolar field...
High intensity heavy ion beams are a main constituent of the FAIR research program. They will be provided by the UNILAC via the high current injector HSI. Generated in high current sources, these ions originally have low charge states. To allow for efficient acceleration in the UNILAC and SIS18, a gas stripper is located at the end of the HSI to reduce the mass-to-charge ratio below 8.5. An...
Provisions are being made in the Electron Ion Collider (EIC) design for future installation of a second Interaction Region (IR), in addition to the day-one primary IR [1]. The envisioned location for the second IR is the existing experi- mental hall at RHIC IP8. It is designed to work with the same beam energy combinations as the first IR, covering a full range of the center-of-mass energy of...
The implementation and further improvements of superconducting undulators is part of the European XFEL facility development program. Within this program, a magnetic field test facility is being developed. Named SUNDAE2 (Superconducting UNDulAtor Experiment 2), it aims to perform in-vacuum magnetic field measurements of superconducting undulators (SCUs) with three techniques: Hall probe, moving...
Wakefields kick the electron bunch to a non-linear tilt causing emittance growth. Any additional correlation like an energy chirp (energy vs z dependence) will filament the disturbance further causing a nearly unrecoverable bigger emittance. For C3 (Cool Copper Collider) the emittance preservation numbers seems to be about 1000 times more stringent than achieved. It is actually "only" about 30...
The Electron Ion Collier (EIC) will utilize highly polarized electron and ion beams. To preserve polarization through numerous depolarizing resonances over the whole EIC hadron accelerator chain, harmonic orbit correction, partial snakes,horizontal tune jump system and full snakes have been used. A new scheme using skew quadrupoles to compensate horizontal intrinsic resonances is under...
RadiaBeam, in collaboration with UCLA and Fermilab, is developing a strongly tapered helical undulator system for the Tapering Enhanced Stimulated Superradiant Amplification experiment at 515 nm (TESSA-515). The experiment will be carried out at the FAST facility at Fermilab as a Gamma-Ray high Efficiency ENhanced Source (FAST-GREENS). The undulator system was designed by UCLA, engineered by...
The collimation system of the electron-positron Future Circular Collider (FCC-ee) will have two main tasks: protect equipment from the multi-MJ beams and mitigate detector backgrounds. An integrated collimation system layout is presented, including beam halo collimation system in one insertion and synchrotron radiation collimation around the experimental interaction points. The Z-production...
Wuhan Advanced Light Source (WALS) is the low-energy 4th generation advanced light source, which is proposed by Wuhan, China. WALS includes a 1.5 GeV full-energy LINAC injector, a 180 m circumference, 1.5 GeV low-emittance storage ring, and a series of start-of-the-art beam lines. The standard 7BA magnetic focusing structure is adopted for the storage ring to lower the beam natural emittance...
The South Advanced Photon Source (SAPS) is a newly proposed storage ring (SR) based photon source project operating at the beam energy of 3.5GeV. To achieve X-ray diffraction-limited in the SR with high density bunch, larger coupling impedance brought by more compact beam pipe structure is inevitable, which makes the beam collective effects be one of the major challenges to the physical...
To further enhance the accelerating gradient of accelerators, we designed a cryogenic C-band standing wave bi-periodic accelerating structure for the Shanghai Soft X-ray Free Electron Laser Facility (SXFEL). According to the low-temperature environment, material characteristics and technological conditions, the design is completed and it is decided to design the accelerating structure into a...
A SLED (SLac Energy Doubler) RF pulse compressor is a passive RF component which increases the peak RF power level at the cost of reducing the pulse length. The Canadian Light Source (CLS) plans to replace the current 250 MeV Linac with a new one in mid-2024 by RI Research Instruments GmbH. The new Linac has a similar energy and two of its three 5.3 m TW constant-gradient accelerating...
The Diamond-II storage ring has been designed to increase photon brightness by up to two orders of magnitude compared to the existing Diamond facility. A single-bunch aperture sharing injection scheme using short stripline kickers applied with high-voltage nano-second pulsers was proposed to provide both high injection efficiency and high photon beam stability in top-up mode [1]. The...
A fourth generation storage ring with an energy of 3 GeV is proposed by Institute of Advanced Science Facilities, Shenzhen. After repeated optimization, the storage ring achieved a dynamic aperture of 15mm. With a relatively large dynamic aperture, Off-axis injection scheme is possible for SILF storage ring. We first considered conventional local bump injection as a candidate. The nonlinear...
SIRIUS is the 4th generation synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS). SIRIUS is currently operating with six beamlines and eight others are at different stages of deployment. In this work we report on the development of simulation tools to analyze the impact of insertion devices (IDs) on SIRIUS beam orbit, optics and dynamic aperture...
Optimization and realistic estimates of the sensitivity of the measurement of charged particle Electric Dipole Moment (EDM) in storage rings require a good understanding of systematic errors that can contribute to a vertical spin build-up mimicking the EDM signal to be detected. A specific case of systematic effect due to offsets of electrostatic bendings and longitudinal magnetic fields is...
The Korea fourth generation storage ring (Korea-4GSR) is a 4GeV, low emittance light source to be built in Ochang, Korea. The booster ring, which consists of 26 FODO standard cells and 2 dispersion-free cells, ramps the beam energy up from 200 MeV to 4 GeV as part of the injector. The circumference and repetition rate of the booster ring is 772.9 m and 2 Hz, respectively. In this paper, the...
Laser Compton Scattering (LCS) is a technique to produce quasi-monochromatic X-rays and gamma rays by colliding a laser with a high-energy electron beam produced by an accelerator. Although LCS light sources are expected to produce photons of the same quality in a small (6m x 8m) device as those from large synchrotron radiation facilities , the low number of scattered photons is an issue for...
The High Energy Photon Source (HEPS) is a 1360.4-m, 6-GeV, ultralow-emittance light source, being built in the suburb of Beijing, China. The HEPS booster contains 128 dipoles,148 quadrupoles and 68 sextupoles, which are divided into several groups. The magnets in one group are connected in series, and powered by a single power supply. To minimize the impact on beam dynamics, magnets sorting...
In this paper,we combines the problems in the determination of the adjustment weight of the current control network and the increasingly updated information processing model, taking the typical level network and making rational use of the function of MATLAB to systematically study the determination of the weight in the adjustment of control network.A variety of objective weighting methods are...
One of the main characteristics of the future light sources like Elettra 2.0 is the small vacuum chamber cross section. In fact, the resistive-wall (RW) impedance due to the small vacuum chambers cross section enhances transverse coupled-bunch instabilities. In this study, the effect of the RW in the multi-bunch case is investigated versus chromaticity. The threshold currents in the presence...
The Superconducting Electron Accelerator Lab (SEALab)* is the SRF-accelerator physics research facility at HZB created in 2021 following official completion of the bERLinPro project. It provides opportunities for SRF-accelerator related research beyond the ERL program, yet ERL-related research continues in this facility (“bERLinPro@SEALab”).
The first stage of commissioning and operation...
The Electron-Ion Collider has an electron storage ring (ESR) and a hadron storage ring (HSR) with beams traveling in opposite directions that collide initially at one but eventually at two interaction points. Our desired machine configurations require a wide range of energies for both rings: 5 to 18 GeV in the ESR, and 41 to 275 GeV/u in the HSR. The range of velocities in the HSR requires...
Previous TDR studies for the SOLEIL II Upgrade project have converged towards a lattice alternating 7BA and 4BA HOA type cells providing a low natural horizontal emittance value in the 80 pm.rad range at an energy of 2.75 GeV. This lattice adapts to the current tunnel geometry as well as to preserve as much as possible the present beamline positions. The new TDR lattice is an evolution...
High-intensity, monochromatic X and 𝛾-rays are a powerful tool for applied science in all fields. Free-Electrons Lasers can generate soft X-rays. A magnetic undulator's shortest possible oscillation period is ~1 cm, which restricts the photon energy to hundreds of keV at GeV-range electron energies. Inverse Compton Scattering, which needs powerful lasers, may provide hard X-rays and...
SIS100 is a new superconducting heavy ion synchrotron optimized for the acceleration of high intensity heavy ion beams. Most crucial intensity limitation for heavy ion beams in SIS100 is the dynamic vacuum and corresponding beam loss by projectile ionization. Ionization loss and ion induced desorption drive the residual gas pressure into an instability, generating an intensity barrier at much...
Recently, we completed a performance upgrade of Test Lab klystron-modulator system for PLS-II RF Linac as well as new developed S-Band 80-MW klystron test. PLS-II main linac system are under an operation of 17 RF stations including S-Band 80-MW klystron. It will be used as a test station for a performance test of RF components for PLS-II RF Linac. Klystron as RF sources is one of critical...
In the Advanced Photon Source Upgrade storage ring, the horizontal collimators protect the rest of the machine from whole beam aborts; however, as shown in previous experiments, the collimators themselves must also be protected from the full intensity of the lost store. The suitability of a vertically-deflecting fan-out kicker was evaluated experimentally. Aborted beam strikes the surface of...
The CERN Linear Accelerator for Research (CLEAR) is a test facility delivering an electron beam in the 30-220 MeV energy range to a diverse user community. In 2022, several hardware and software upgrades were done to the main installation, and procedures and methods were developed to address specific user requirements, including a further extension of the beam parameter ranges. In the paper,...
The Electron-Ion Collider polarized pre-injector is designed to generate a 7 nC with eight bunches every second to inject into the Rapid Cycling Synchrotron. The pre-injector includes the polarized electron source, bunching section, traveling wave plate (TWP) LINAC, and longitudinal phase space manipulation. A compact zig-zag chicane, and dechirp cavity are used to rotate the bunch in...
The ultimate goal of studying spin-radial motion in a ring with "Quasi-Frozen Spin" is to develop a procedure for measuring the deuteron electric dipole moment. For a ring with a "Frozen Spin", the authors developed the Frequency Domain Method. A distinctive feature of a ring with a "Quasi-Frozen Spin" is spin oscillation with a small amplitude around the direction of motion. In this work, we...
The European Spallation Source neutrino Super Beam plus (ESSνSB+) project has recently been approved by the EU for a 4-year design study. It aims at measuring the neutrino-nucleus cross-section, which represents the dominant systematic uncertainty in the measurement, in the energy range of 0.2 – 0.6 GeV, as well as perform searches for sterile neutrinos using a Low Energy nuSTORM (LEnuSTORM)...
The Frascati linear accelerator was used as electron and positron source for the DAFNE collider and the Beam Test Facility (BTF) where the fixed target experiments as PADME or irradiation test for space components are ongoing.
Builded in 1996 an upgrade of the L-C traditional resonant charging system is started in 2018 and today 3 of the 4 RF power stations modulator are upgraded from the...
High Energy Photon Source is a 6 GeV diffraction-limited synchrotron light source currently under construction in Beijing. To provide the required 6 MV of RF voltage and 850 kW of beam power, five 166.6 MHz superconducting quarter-wave beta=1 cavities have been chosen for the fundamental RF system of the storage ring. Each cavity will be equipped with one fundamental power coupler (FPC)...
The IFMIF RFQ has to accelerate a D+ beam of 125 mA
from the source energy of 100 keV to its final energy of 5
MeV. For such a purpose, the needed RF power
(approximately 600 kW dissipated power and 600 kW beam
power) is injected in the RFQ from 8 amplifier chains with
8 coupling loops. In order to quantitatively understand the
different circumstances which can occur, an...
The Beijing Electron-Positron Collider II (BEPC-II) is a 1.89 GeV two-ring e+/e- collider. It consists of two superconducting (SC) cavities in the ring and the design of the cavity is the same as the ones used in HEPS (High Energy Photo source) storage ring. During operation of the SC cavities of BEPC-II, sideband close to 46 Hz and 100 Hz were found, which decreased the controlling accuracy...
Following a 3-year long shutdown for upgrade and consolidation work, the LHC was re-commissioned in spring 2022, achieving a new record of 6.8 TeV per beam. This paper will describe the beam commissioning phase, the electron cloud conditioning, and the intensity ramp-up bringing the machine to a steady production state. The main issues and achievements will be presented, including the fully...
The Elettra 2.0 upgrade project requires the realization of a new storage ring that will replace the existing one of Elettra. The Elettra 2.0 optic, developed on the basis of the magnet feasibility studies, include a total of 552 iron-dominated electro magnets, with all sextupoles and octupoles equipped with additional coils to achieve the combined fields of corrector and skew quadrupoles....
The existing post-stripper Drift Tube LINAC (DTL) of the GSI UNILAC will be replaced with the new Alvarez 2.0 DTL to serve within the injector chain for the Facility for Antiproton and Ion Research (FAIR). The 108.4 MHz Alvarez 2.0 DTL accelerates intense ion beams along five individual cavities with a total length of 55 meters from 1.36 MeV/u to 11.32 MeV/u. The design of the Alvarez 2.0 DTL...
A new linear induction accelerator named Scorpius is being designed for multi-pulse flash radiography. The solid-state pulsed power system offers a technological breakthrough by delivering multiple independent pulses to accommodate a wide variety of pulse formats. The design provides pulse modulation capabilities which will mitigate reflected waves and reduce voltage variations across a...
The Future Circular electron-positron Collider, FCC- ee, is designed for unprecedented precision for particle physics experiments from the Z-pole up to above the top-pair-threshold, corresponding to a beam energy range from 45.6 to 182.5 GeV. Performing collisions at various particle-physics resonances requires precise knowledge of the centre-of-mass energy (ECM) and collision boosts at all...
We present the latest development for the FCC-ee interaction region. It represents a major challenge for the FCC-ee collider, which has to achieve extremely high luminosity over a wide range of centre-of-mass energies. The FCC-ee will host two or four high-precision experiments. The machine parameters have to be well controlled and the design of the machine-detector-interface has to be...
Polarization control of undulator radiation attracts a great attention due to its application prospects in material and biology. Various undulators have been developed to obtain radiation of specific polarization states. In the electron storage ring light source, different methods have been proposed to realize a specific polarization switching. However, there is still a strong demanding to...
The Korea-4GSR with low emittance of 60 pm-rad provides the photon beam that is 100 times brighter and 100 times more coherent than PLS-II. Despite these powerful advantages, the new source imposes high power density on beamline optics. In particular, the first mirror M1 receiving broadband white beam will be directly affected. To check this, we calculated the power density by introducing a...
A new electron cooling experiment is being planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab for cooling ~2.5 MeV protons in the presence of intense space-charge. Electron cooling is integral to the study of beam dynamics and has valuable applications for producing high-intensity hadron beams in particle accelerators. For such goals, an electron lens to be placed in the IOTA...
Ionization cooling is the only suitable approach to reduce the phase space volume occupied by a muon beam on a timescale compatible with the muon lifetime. Small normalized transversal emittances can be achieved by using hydrogen (H) as an absorber and high solenoid fields at low beam energy. The strong focusing suppresses emittance growth due to scattering occurring from muon beam interaction...
The SuperKEKB accelerator is currently in operation in Tsukuba, Japan, with a planned long shutdown in 2026. Among the possible upgrades being considered during this period is the change to a polarized electron beam in the High Energy Ring. Such a change would require modifications in the source generation and transport, geometrical and lattice variations to provide spin rotation, and...
During the injection phase of the Higgs mode of CEPC, the stored energy of the cavity is low and beam loading is relatively high. The synchrotron radiation damping is weak compared to the growth rate of the untidamped mode. This will cause two types of trouble. Firstly, the transient beam loading caused phase-shift between the head and the tail of the beam will be too much. Secondly, the...
During the on-axis injection process under the Higgs model, the transient beam loading in the CEPC storage ring will cause a phase shift between the head and the tail of one beam. Since the missing bunches are only extracted from one of the beams at a time, there will be a misalignment between the colliding bunches at the IP. In this paper, we presented the results of the study on this...
Matched first order transition crossing in the Relativistic Heavy Ion Collider (RHIC) is performed by using two families of jump quadrupoles when ramping species through transition to storage energy. The jump quadrupole families control $\gamma$ transition and the working point of the accelerator by compensating for the tune shift from the jump and minimizing optical distortions. After...
We investigate the upgrade of Elettra 2.0 to radio-frequency transverse deflecting cavities generating a steady-state vertical deflection of selected electron bunches. The study demonstrates the feasibility of 1 to few ps-long x-ray pulses at MHz repetition rate provided simultaneously to several beamlines, and transparent to the standard multi-bunch operation. The short pulse exhibits total...
Transverse Resonant Island Buckets (TRIBs*) can be established by moving the horizontal tune close to a third order resonance. In this case the TRIBs correspond to a second stable orbit, longitudinally winding around the core orbit in the transverse x-x’-phasespace and closing after three revolutions. TRIBs provide many potential application possibilities ranging amongst others from simple...
The concept of Transverse Resonance Island Buckets (TRIBs) has recently gained attention in the storage ring light source community, and has found usage to, e.g., serve timing users and can enable fast polarity switching of the light in undulators.
This contribution introduces two options for creating TRIBs in SLS 2.0 using either 3Qx or 4Qx resonances. Options for control of the islands...
Inverse Compton Scattering (ICS) is an ideal source of tunable monochromatic gamma rays. These gammas have uses for Nuclear Resonance Fluorescence, and production of novel medical radioisotopes. The gamma energy can be tuned by changing the electron energy. An ICS source can be made quasi-monochromatic by using low energy spread electron and laser beams, and using a collimator.
Currently...
We report on experimental investigations of a single electron, circulating in the Fermilab IOTA storage ring, focusing on two-photon undulator emissions. We employ a Mach-Zehnder (MZ) interferometer for the undulator radiation to determine the photon coherence length as well as to measure its statistical properties. In this experiment, the pulse of radiation in one arm of the interferometer...
The performance requirements for next generation electron accelerators put ever increasing demand on the photocathode performance, where it fundamentally limits the achievable beam quality. Metal photocathodes are limited by their high work function and relatively low quantum efficiency, necessitating the use of high powered deep UV lasers. Metal oxide thin film interfaces have been shown to...
HZB is in the process of developing a concept for a successor to the BESSY II synchrotron facility. The new facility will build on the strengths developed in Berlin over the last twenty years in delivering flexibly polarised soft X-Rays to dozens of beamlines. The successor facility BESSY III is planned to operate at 2.5GeV, in comparison to the 1.7GeV operation of BESSY II. This makes it...
The codes UNDUMAG and WAVE have been developed at HZB/BESSY. They are used
intensively to design undulators, and to understand their magnetic and
synchrotron radiation properties, as well as their impact on the storage ring.
Recent extensions will be presented. A more intuitive input file to define
undulator geometry has been developed, as well as a Python based GUI that
allows the...
The studies and R&D on the high-intensity positron source for the FCC-ee have been initiated for a while. The positrons are produced by a 6 GeV electron drive-beam incident on a target-converter at 200 Hz. The drive beam comes in 2 bunches spaced by 25 ns with a maximum charge of ~5 nC per bunch. Two scenarios using conventional and hybrid targets are being studied for positron production....
The High Luminosity Large Hadron Collider (HL-LHC) is an ongoing project to upgrade the LHC, to increase the instantaneous luminosity by a factor of five compared to the nominal LHC and reach an integrated luminosity of 3000~fb$^{-1}$ in the first ten years. One of the driving factors to achieve this goal is an increase of the bunch population from $1.15\cdot10^{11}$ to $2.2\cdot10^{11}$...
This publication builds on previous studies that explore the use of MAD-X and SAD to simulate FCC-ee. In particular, we examine further optics properties as well as single particle tracking. Compared to previous iterations, this work also introduces a comparison to XSuite and discusses how the different codes fit in a cohesive FCC-ee strategy.
The Diamond-II storage ring lattice has continued to be developed after publication of the Diamond-II’s technical design report. This study provides the updated information needed for the commissioning simulation. Firstly, changes to the reference lattice and phase-one insertion devices are briefly described. Then the error specifications are amended to be consistent with the magnet...
Siam Photon Source (SPS) is an existing synchrotron light source in Thailand, which has been operated and provided synchrotron radiation for user beam service for more than 20 years. The SPS accelerator system con-sists of a 40-MeV linac, a 1.2-GeV booster synchrotron and a storage ring with double bend achromat (DBA) lattice. The linac is one of the most critical parts of the SPS machine in...
Located between the Delivery Ring and the Mu2e experiment in the Muon campus, the M4 beamline serves as the transport line for a resonantly extracted, 8kW, 8GeV pulsed proton beam to the Mu2e production target. In addition to challenges posed by elevation and directional changes, the M4 line is tasked with removing beam halo from resonant extraction and ensuring adequate inter-pulse beam...
A matching device with a strong magnetic field is used to capture positrons in the positron source of future e+e- colliders such as the Compact LInear Collider (CLIC) and the Future Circular Collider (FCC-ee). Compared to conventional matching devices such as flux concentrators, superconducting (SC) solenoids can have a much higher peak field, improving the capture efficiency and the positron...
V3Si is an A-15 SC that has a relatively higher Critical Temperature Tc (17 K), compared to niobium (Nb) and can maintain a higher critical field than Nb [1]. These properties would in theory allow thin film V3Si superconducting RF-accelerator (SRF) cavities to operate at higher temperatures and with greater accelerator voltages, compared to Niobium cavities. However, this would require the...
The main accelerator of WALS (Wuhan Advanced Light Source) is a 1.5 GeV, 180 m storage ring with emittance 222.8 pm.rad, which reaches soft X-Ray diffraction limit. To achieve such low emittance, the magnet system is designed very compact with very small aperture. And this results in a narrow transition structure and a low flow conductivity vacuum chamber. In consideration of the beam...
The future Electron-Ion Collider (EIC) adopts a horizontal crab crossing scheme to compensate for the geometric luminosity loss from a 25 mrad crossing angle. The crab cavity noise-induced emittance growth in the deflecting plane (horizontal for EIC) has been well studied and a feedback system is effective to suppress the growth. However, simulations also showed emittance growth in the...
The SuperKEKB accelerator, a 7 GeV electron and a 4 GeV positron double-ring collider, is in progress in order to explore the new physics beyond the standard model.
The next milestone is to obtain integrated luminosity of 15 /ab data in the next decade,
so that the luminosity should exceed 2 x 10^35 /cm^2/s in several years.
One of the essential issues is the injection performances for both...
Alongside the new LCLS-II facility, a new electron beamline known as Linac to End Station A (LESA) is under construction at SLAC. LESA will use field-emitted dark current from the new superconducting accelerator to search for MeV- to GeV-scale dark matter. To predict the behavior of the dark current in LESA, we must account for the effects of wakefields. In the conventional analysis of...
The material for this paper/poster has been merged with WEPL037:
Robust design of modern Chasman-Green lattices – a geometric control theory approach
In intraoperative radiation therapy (IORT), accelerators typically consist of two or more tubes to achieve adjusta-ble electron energy. To simplify the accelerator structure and meet the demand for convenient adjustment of elec-tron energy, we propose an X-band electron linear accel-erator for IORT, composed of 102 cavities. This accelera-tor can adjust the output electron energy over a large...
