Particle accelerators have long been instrumental in advancing scientific research, medical treatments, and industrial processes. However, traditional radio-frequency accelerators are encumbered by their size, expense, and reliance on external microwave sources.
In this paper, we propose a novel linear accelerator concept that integrates a high-power microwave source directly into the...
A compact TM020-mode radiofrequency (RF) cavity has been proposed and studied by KEK and RIKEN for storage ring of Nanoterasu facility. However, the leakage power of the accelerating mode into the coaxial slots is an issue to limit its performance. This paper presents an improved TM020-mode cavity in order to solve this issue. To protect the operating mode and reduce its leak-age, a choke...
The SEALab facility in Berlin is home to an R\&D superconducting radio-frequency (SRF)photoinjector setup and beamline. Designed to support multiple varied applications - ranging from Energy Recovery Linac (ERL) to Ultrafast Electron Diffraction (UED) and Electron-Beam Water Treatment (EBWT) - SEALab requires flexible, high-precision tuning to support these diverse beam modes. These...
The CLEAR (CERN Linear Electron Accelerator for Research) facility delivers to a wide user community a 200 MeV electron beam with highly flexible parameters.
Running conditions range from single-bunch to multi-bunch operation, with bunch charges from 10 pC to 1 nC, bunch durations from 100 fs to tens of ps, and
includes tunable momentum (30 MeV/c to 220 MeV/c).
Such a variety of beam...
The properties of the photoemitting electron sources are the determining factors contributing to the performance of the most advanced electron accelerator applications such as particle colliders, X-ray free electron lasers, ultra-fast electron diffraction and microscopy experiments. Therefore, low mean transverse energy (MTE), high quantum efficiency (QE) along with long operational lifetime...
Heavy ion therapy (HIT) is a transformative approach to cancer treatment offering precision to target tumors minimizing damage to surrounding normal tissue cells. This study explores the feasibility of applying the particle-in-cell (PIC) method to evaluate and optimize the clinical therapy of HIT. The PIC models ion beams & dynamics by tracking their motion with electromagnetic interaction and...
The International Linear Collider (ILC) is a next-generation electron-positron collider based on the superconducting linear accelerator. Many positrons are required for the ILC because beams are not reused in linear colliders. Therefore, the ILC electron-driven (E-driven) positron source system should be designed to optimize efficient positron generation. In this study, we optimize the...
Ion accelerators use electron cooling to improve luminosity and beam lifetime. However, extremely low momentum spread in a cold beam weakens Landau damping, enabling the development of instabilities and potentially decreasing lifetime. To combat this, the NICA Booster electron cooling system allows to generate electron beams with oscillating energy to increase the momentum spread in ion beams....
Ångström and attosecond represent fundamental spatiotemporal scales for studying electron dynamics in various materials. Recently, high-power attosecond hard X-ray pulses have been successfully demonstrated at the European XFEL using the self-chirping operation mode. However, the current process heavily depends on manual tuning by experienced operators, which is time-intensive and less...
FCC-ee luminosity optimization relies on measuring realistic signals from Bhabha scattering, beamstrahlung, and radiative Bhabha photons. Initial assessments of beamstrahlung signals examine the change in luminosity, beamstrahlung power and vertex detector hits in response to waist shifts, vertical dispersion and skew coupling at the collision point. These ongoing studies aim to extract...
Developing medical accelerators for clinical use presents significant challenges, particularly for FLASH radiotherapy, where specific beam parameters are essential to activate the FLASH effect. At Sapienza University, a new electron FLASH LINAC is being developed, designed to deliver FLASH electrons and adaptable for very high-energy electron (VHEE) applications. This work focuses on...
Muon colliders promise an efficient path to a multi-TeV energy collider facility. In the greenfield study, the final stage of the acceleration chain is planned as a series of four rapid-cycling synchrotrons (RCS). In each RCS, the RF systems are divided into several sections and shared by the two counter-rotating muon bunches. The accelerator requirements are driven by the need to preserve a...
Intra-beam scattering (IBS) has recently gained significant interest in the community of free electron lasers (FELs), as it is believed to produce an increment in the sliced energy spread (SES), which is detrimental to FEL performance. To control and contain this phenomenon, it is important to include IBS in the design phase of an FEL through appropriate numerical simulation. Most existing...
Cavity beam position monitors (CBPMs) are very high-precision devices that, in recent years, have progressed from experimental equipment to standard linac diagnostics in many prominent facilities, most notably free electron lasers. However, the high sensitivity of these devices comes at the cost of a limited measurement range, even with high dynamic range electronics. Furthermore, CBPMs need...
The CERN Proton Synchrotron Booster (PSB) delivers a wide variety of high-intensity and high-brightness proton beams to several destinations, including operations at the Large Hadron Collider (LHC) and various fixed-target experiments. Following the Long Shutdown 2 (LS2) upgrades, discrepancies between beam measurements and macro-particle simulations were observed, highlighting the need for a...
Beam stacking is a key advantage of Fixed Field alternating gradient Accelerators (FFAs) for high-intensity applications. During stacking, one beam is stored as a coasting beam at the extraction energy while another, incoming beam is accelerated. However, the beam loss mechanism termed RF knockout can occur during stacking and undermine gains in extracted beam current. The accelerating RF...
High current linear accelerators require the precise alignment of accelerating cavities to maintain a high beam quality. The PERLE (Powerful Energy Recovery Linac for Experiments) injector cryomodule is composed of four single-cell cavities, each of which can be independently tuned to allow greater control of the beam at this crucial point. Misalignments can lead to perturbations in the beam...
We conducted time-of-flight (TOF) measurements to characterize the spectrum of a quasi-monoenergetic neutron beam driven by a 30-MeV proton cyclotron at the National Atomic Research Institute in Taiwan*. Neutrons were produced by irradiating 30-MeV protons onto a 1-mm-thick beryllium target. The developed TOF spectrometer comprised two 2-inch EJ-309 organic scintillators positioned 200 mm from...
We study the coherent synchrotron radiation instability in a novel synchrotron light source concept, steady-state microbunching storage ring.
Xsuite is a collection of packages developed to simulate beam dynamics in particle accelerators. It includes Python modules (Xobjects, Xpart, Xtrack, Xcoll, Xfields, Xdeps) that can be seamlessly integrated with one another and with both accelerator-specific and general-purpose Python tools, enabling the study of complex simulation scenarios. The Xcoll module, developed for collimation...
The insertion devices (IDs) can severely affect the beam dynamics of a storage ring. Recently, a new elliptically polarizing undulator(EPU) is installed in the Hefei Light Source II (HLS-II) storage ring. The effects of this EPU can be modeled using the kick map method. In this paper, we present the kick map of the EPU with vertical mode and how it affects the beam dynamics. Since the HLS-II...
The negative impacts of global warming and continuously rising energy costs emphasize a need for sustainable and cost-effective operation also for accelerator facilities. This necessitates optimization of accelerator operation, which then requires a comprehensive profiling of accelerator facilities for power consumption patterns to break down the consumption trends of the whole facility. At...
In recent years, proton and heavy-ion therapy has become increasingly widespread in clinical applications, and has emerged as one of the important means for cancer treatment. The commonly used particle types for this therapy are protons and carbon ions. However, further research into the biological effect has found that helium ions have both high biological effectiveness and small penumbra...
Round beam operation is considered for the planned ultra-low emittance storage ring PETRA IV at DESY, Hamburg. With a natural emittance of 20 pm rad, we evaluate and discuss the advantages and challenges of sharing the emittance between transversal planes. The effect on single and coupled bunch instability thresholds, intra-beam scattering rates and Touschek lifetime of this operation mode are...
Beam-based studies at the LHC injection energy showed that compensation of the strongly driven sextupolar resonance, Qx+2Qy, improved both the dynamic aperture and lifetime of the beam, even when far from the working point and on the far side of the 3Qy resonance. Thus, a reduction of other strong normal sextupolar resonance sources was of interest. In 2024, the first measurements of resonance...
The construction of fourth-generation accelerators, represented by free-electron lasers and diffraction-limited storage rings, is increasingly popular, which sets higher standards for the installation precision of insertion devices. Large-scale insertion devices are installed using two laser trackers, but a rigorous system has not been established. To enhance installation accuracy, we propose...
Magnetic hysteresis and eddy current decay continue to challenge beam quality and operational consistency in multi-cycling machines like the Super Proton Synchrotron (SPS) at CERN. Building on our previous work, this paper presents improvements in the data-driven approach for magnetic field modelling to enhance the reproducibility of SPS dipole and quadrupole fields and thus maintain stable...
The next generation Australian Synchrotron project (AS2), is a proposed 4th generation light source, aims to deliver ultra-low emittance $\sim$100 pm-radians and highly coherent, bright light. Constraints on emittance place tight demands on beam optics correction techniques like linear optics of closed orbit (LOCO) and consequently constraints on accurate estimation of the beam centroid along...
In recent years, several new beam manipulation techniques have been proposed that exploit the crossing of nonlinear resonances and the use of stable islands of the transverse phase space. One such manipulation is a novel approach to slow extraction, which combines particle trapping in stable islands with the use of bent crystals to reduce losses on the extraction septum. As a first step...
This paper presents the design of 750 MHz IH-DTL (Interdigital H-mode Drift Tube Linac) tank, specifically developed to be part of a carbon ion injector for medical treatment applications. These sections provide a highly efficient solution for ion acceleration in the 5 to 10 MeV per nucleon energy range, offering a high shunt impedance. The study includes simulations of electromagnetic fields...
Linear accelerators offer key advantages over circular machines in hadron therapy, such as rapid energy modulation and reduced activation. In this work, we optimized a 3~GHz Side-Coupled Drift Tube Linac (SCDTL) in terms of energy efficiency and the maximum achievable acceleration voltage. Comparative analyses were performed with alternative optimized configurations in TE and TM modes for ions...
In order to fill the gap of X-ray intraoperative radiotherapy technology in China, an X-band standing wave electron linear accelerator with operating frequency of 9.3 GHz was designed for X-ray intraoperative radiotherapy equipment. Using electromagnetic simulation software and beam dynamics simulation software, the outlet energy of the accelerator is 50 keV , and the electron capture...
A novel high-precision beam diagnostic system has been designed for slice emittance and energy spread measurements. The 20-meter diagnostic platform integrates eight quadrupoles, a deflecting cavity, and an energy spectrometer, achieving 100fs temporal resolution in both operational modes through the same beamline layout. The emittance measurement mode provides 50-fold horizontal...
LhARA, which stands for “Laser-hybrid Accelerator for
Radiobiological Applications”, is a novel and flexible facil-
ity dedicated to research in radiobiology. A proton beam
of energy up to 15 MeV can be produced by a laser driven
source, the beam then enters a Fixed Field Alternating (FFA)
gradient accelerator for acceleration to produce a variable ex-
traction energy between 15-127 MeV....
The grid control power supply of the electron gun of the free electron laser (FEL) is a high frequency pulse power supply (HF-PPS), which has a special time structure. The macro pulse repetition frequency of the HF-PPS designed in this paper is 10 Hz, and the micro pulse repetition frequency is 476 MHz.
A collaboration is underway to experimentally demonstrate a novel approach using deflecting cavities to control a particle beam’s longitudinal chirp. While a series of deflecting cavities produces negative chirp, the de-chirping process requires additional modification on the beamline. It has been known that inserting negative drift sections between TDCs enables de-chirping. While the original...
The high current density of HTS material allows electromagnet to induce sufficiently strong magnetic field without relying on any iron core. This permits the design of air-cored cyclotron, where the absence of iron core brings the properties of light-weight and high field reproducibility, making it an ideal medical cyclotron to be installed inside hospitals. However, the cyclotron coil system...
The advancement of broadband terahertz (THz) sources has become increasingly important for various scientific and technological applications, including those in particle accelerators. To enable tunable and flexible THz source development, components capable of selective THz spectrum filtering are essential. In this work, we investigate the use of 3D-printed photonic crystal structures,...
The paper presents a design of an autocorrelator manufactured to measure the duration of infrared picosecond pulses of radiation from the 3rd laser of the Novosibirsk Free Electron Laser facility, as well as the results of testing the autocorrelator when measuring the duration of picosecond pulses in the visible range. The results and future plans for future experiments using developed autocorrelator
In this paper, a multipurpose beam diagnostic system based on a YAG:Ce scintillator is presented. This system was developed in order to measure beam profile, transverse parameters, momentum spectrum, and current of the electrostatic accelerator. The concerning issues in the beam profile monitor design such as image resolution and scintillator temperature distribution have been discussed. In...
A cavity beam position monitor (cBPM) developed by
CEA Saclay was installed at the end of the Accelerator Test
Facility (ATF) linac to evaluate the combined performance
of the monitor and its associated signal processing system.
The setup incorporates a down-conversion architecture inspired
by Royal Holloway, University of London (RHUL),
and employs a digital down-conversion (DDC)...
Effect assessments of high-energy radiations on materials and equipment are expected to become increasingly important in near future space developments. We initiated a project to construct an irradiation environment with high-energy radiations using the electron linear accelerator at Nihon University. The advantages of using this accelerator include the accelerations up to 100 MeV for...
An integrated concept is presented to design a permanent quadrupole magnet (PQM) using tunning modules simultaneously for varying magnetic field gradient. It is anticipated that this design will be utilized for Hefei Advanced Light Facility (HALF) in the future. This design leverages symmetry to achieve both a broad range of magnetic field gradient tunning and a narrow range of precise...
In the scope of the renewal of its injection systems, the ESRF-EBS has decided to implement a new scheme using Non-Linear Kickers (NLK) magnets. These pulsed octupole like magnets are extremely sensitive to any misalignment of the conductors carrying the currents resulting in a degraded magnetic field quality. It is then important to characterize precisely the transverse magnetic fields of...
Slow beam the extraction in synchrotrons is utilized for various nuclear and particle physics experiments and radiology. A beam loss at a septum electrode induces equipment activation and damage. We have been developing a non-destructive electrostatic septum. This septum has multiple electrodes, and those are placed around the outside of the beam. Measuring the 2-D electric field distribution...
Coherent Synchrotron Radiation (CSR) plays a critical role in beam dynamics, significantly influencing beam shape and energy characteristics in particle accelerators. This study investigates the CSR effect through a comprehensive numerical approach, starting from the fundamental Lienard-Wiechert equation and utilizing an explicit, non-approximated methodology to explore beam energy dynamics....
In the SuperKEKB/Belle-II experiment, various new physics searches are conducted by colliding 4 GeV positrons and 7 GeV electrons. Future plans aim to significantly increase luminosity, targeting an integrated luminosity 100 times higher than current levels. However, the realization of this goal is challenged by the phenomenon of "Sudden Beam Loss" (SBL), characterized by the abrupt...
The effectiveness and efficiency of a beam injection scheme is crucial
to achieve high beam intensities while minimizing possible beam losses.
The classical method for injecting from a linac to a synchrotron is
the multi-turn injection. In this scheme the quality of the injected
beam as well as of the injection scheme depends on factors as beam
emittance, type of local bump ramp,...
Coupled bunch instability was observed during beam commissioning of CSNS/RCS. The instability was successfully suppressed by installing sextupoles to control chromaticity. The instability exhibits characteristics influenced by the strength of space charge. We conducted a theoretical study on the effects of chromaticity and space charge on coupled bunch instability and compared results with...
The Advanced Wakefield Experiment (AWAKE) at CERN uses bunches from the CERN SPS to develop proton-driven plasma wakefield acceleration. AWAKE Run 2c (starting in 2029) plans for external on-axis injection of a 150 MeV electron witness bunch. The goal is to demonstrate emittance control of multi-GeV accelerated electron beams. Prior to injection, the electron witness bunch may have to traverse...
Carbon nanotubes (CNTs), known for their versatility as 2D materials, are key to advancing quantum technologies such as qubit fabrication and magnetic data storage. In this study, multi-walled carbon nanotubes (MWCNTs) doped with magnetic impurities (Fe and Co) were exposed to swift heavy ion (SHI) irradiation to explore induced structural modifications. SHI beams transfer energy to the carbon...
Shanghai Synchrotron Radiation Facility/Shanghai Soft X-ray FEL Facility has developed an advanced transverse deflecting structure TTDS (two-mode transverse deflecting structure), using two different rf power sources to deflect beam in any angle. Bandpass filter is a key component in the TTDS, designed to pass low-frequency signals while blocking high-frequency ones. This study uses an...
EuPRAXIA, the "European Plasma Research Accelerator with eXcellence In Applications," represents the next generation of free-electron lasers (FEL). It aims to develop a compact, cost-efficient particle accelerator using innovative wake-field accelerator technology. High-energy physics often demands higher acceleration voltages, and X-band technology offers high gradients in compact structures....
Longitudinal emittance growth is a significant challenge in RF linacs, especially for poorly bunched beams. This stems from particles occupying outer synchrotron oscillation orbits in the LBET, causing unwanted bunch-bunch interactions and degraded beam quality. To address this, we proposed using temporally spaced laser pulses to selectively photo-detach electrons from the longitudinal head...
This study explores the feasibility of using Compton Backscattering (CBS) as a compact source for generating photons in the extreme ultraviolet (EUV) to soft X-ray range, with potential applications in biological imaging and modern lithography. A CBS experiment was conducted at the AWAKE Run 2c test injector (ARTI), where electron bunches, accelerated up to 6 MeV by a high-gradient,...
This theoretical study presents an advanced method for longitudinal phase space tomography in electron storage rings, focusing on reconstructing phase space densities from electro-optical spectral decoding (EOSD) measurements that incorporate crystal geometry effects. The EOSD crystal geometry significantly impacts the measurement signal due to signal integration along its length and...
Symplecticity of the transfer maps is important for reliable evaluation of space-charge dominated beams in accelerators. Unfortunately, most simulation codes that include collective effects, such as space charge, do not use canonical phase-space variables and therefore are not symplectic in the presence of electromagnetic fields. In this paper, we present a numerical method to extract...
The UC Davis Crocker Nuclear Laboratory houses a 72-inch multi-species Isochronous Cyclotron built in the 1960’s. For many years, previously unexplained beam dynamics have been indirectly observed at the cyclotron by both internal and external experimenters. Investigating these effects within the cyclotron, at the bunch level, has proven particularly challenging due to the cyclotron's harsh...
The FCC-ee is a future high-luminosity circular electron-positron collider aiming at achieving unprecedented luminosities with beam energies ranging from 45.6 up to 182.5 GeV. FCC-ee demands precise optics tuning to achieve its ambitious performance goals. This study investigates the tuning and correction of FCC-ee optics under simulated magnet misalignments, with a particular focus on the...
Superconducting radiofrequency cavities made of bulk Nb are reaching their theoretical limits in the maximum accelerating gradient, Eacc, where Eacc is limited by the maximum magnetic field, B, that can be applied on the surface of the accelerating cavity wall. To increase Eacc, the maximum B field, Bmax, which can be applied to the surface, must also be increased. The A15 materials or...
The first experimental observation of a 10 $\mu$m crabbing orbit at 1~$\sigma_z$ induced by head-on collisions with a non-zero crossing angle ($\theta_c$) in a high-energy proton beam at the LHC is presented. This challenging measurement required both the design of a dedicated experiment and a careful calibration and optimization of the beam instrumentation to produce and detect such a subtle...
The microbunching instability (MBI) has long been a persistent issue in high-brightness electron beam transport. The dogleg structure, a dispersive configuration composed of two quadrupole magnets and dipole magnets, has drawn attention in recent studies. It has been pointed out that the Landau damping effect can be enhanced to effectively suppress the microbunching instability by adjusting...
Within the framework of the NIMMS (Next Ion Medical Machine Study) initiative at CERN, a comprehensive design study is being performed for the Helium Light Ion Compact Synchrotron (HeLICS), a compact accelerator for hadron therapy. A key component of this facility is the radiofrequency (RF) cavity. Its proposed design is based on the wideband technology successfully implemented in the CERN PS...
As the High Luminosity LHC (HL-LHC) era approaches, precise control of the accelerator becomes increasingly critical. Machine studies are essential to address the forthcoming challenges and develop correction strategies based on experimental measurements. Although the upgraded inner triplets are not yet available, key features of the HL-LHC optics can still be investigated. This includes...
With the upgrade from PETRA III to PETRA IV the requirements concerning the beam parameters increase. Thus, a special focus is placed on the suppression of higher order modes (HOMs) in the accelerating systems.
An Investigation of the already presented single mode structure showed the emergence of certain higher order modes. These cavity eigenmodes are now examined by evaluating and...
The SRF community has shown that high temperature annealing can improve the flux expulsion of niobium cavities during cooldown. The required temperature will vary between cavities and different batches of material, typically around 800 C and up to 1000 C. However, for niobium with a low residual resistance ratio (RRR), even 1000 C is not enough to improve its poor flux expulsion. The purpose...
Beam stability in the FCC-ee collider is strongly influenced by transverse and longitudinal beam coupling impedance. Developing a flexible and comprehensive impedance model is crucial for accurately evaluating and mitigating instabilities as machine parameters evolve. This study investigates the effect of the FCC-ee collimation system, identifying it as a dominant source of total machine...
Muon colliders offer high-luminosity, multi-TeV collisions without significant synchrotron radiation but require further exploration of muon production, acceleration, cooling, and storage techniques. A proposed 6D cooling demonstrator aims to extend the MICE experiment's validation of transverse ionization cooling to also reduce longitudinal emittance, using bunched muon beams and...
Developing a laser wakefield acceleration (LWFA) scheme by focusing few-TW laser pulses into a thin, dense gas target paves the way for generating high-average-current electron beams driven by a modern high-repetition-rate laser. Our previous study demonstrated that using a sub-mm nitrogen (N₂) gas cell facilitates the routine generation of 10-MeV-scale electron beams from few-TW LWFA with...
National Synchrotron Radiation Research Center (NSRRC) has been advancing its capabilities in producing intense terahertz (THz) radiation from a superradiant free-electron laser (FEL). This system utilizes a photoinjector operating in its velocity bunching mode to achieve ultra-short electron bunches. However, the highest THz frequency from the facility is determined by the shortest achievable...
Betatron radiation is the spontaneous emission of radiation produced by the betatron oscillations of electrons in a plasma during the Laser Wakefield Acceleration (LWFA) process. A high-intensity and ultra-short laser pulse is focused on a supersonic gas jet, simultaneously creating a plasma, injecting, and accelerating electrons, which then emit this radiation. In the framework of the ...
A 2.5 MeV proton injector is being constructed for the IOTA ring at Fermilab to study the interaction of nonlinear integrable optics (NIO) with high space charge beams. Space charge in the transport line from the RFQ to the injection location has a significant current dependent effect on the phase space. Simulation studies to support efficient injection of intense bunches into IOTA are...
The determination of electromagnetic wakefields and their impact on accelerator performance is a longstanding challenge in accelerator physics. These wakefields, induced by the interaction between a charged particle beam and the surrounding vacuum chamber structures, significantly affect beam stability and power dissipation. Accurate characterization of these effects via beam-coupling...
The emission of electrons induced by beam interaction with thin targets is a phenomenon used to measure various properties of particle beams. The main processes of electron emission are: secondary emission, delta electron production and thermionic emission. The last one is not desired, because the intensity of thermionic electrons is not directly related to beam density profile. A common...
Alternative configurations around the ATLAS experiment are investigated aiming to reduce muon rates at forward physics experiments such as FASER and SND@LHC. The Geant4 toolkit BDSIM is used to propagate muons through a model of a section of the LHC and the TI12 tunnel, where the FASER experiment is located. We compare the muon rates in BDSIM with FASER data collected during dedicated tests in...
In plasma-based acceleration, an ultra-relativistic particle
bunch—or an intense laser beam—is used to expel electrons
from its propagation path, forming a wake that is devoid
of electrons. The ions, being significantly more massive,
are often assumed to be stationary. However, both theory
and simulations suggest that any sufficiently dense electron
bunch can trigger ion motion, and its...
Recent results of production of the medical radionuclides 67Cu using a laser wakefield accelerator (LWFA) are presented. This emerging technique utilises powerful, ultrashort laser pulses that are focussed into a gas jet to create a plasma wake that traps and accelerates electrons to very high energies with large accelerating gradients. Accelerated electrons interact with high-Z material to...
The Delhi Light source is a pre-bunched Free Electron Laser facility to generate coherent THz radiation. The electron beam is generated from a normal conducting 2.6 cell RF photocathode (PC) gun operated at 2860 MHz. The RF gun is powered by a high power RF source for a duration of 4 µs at 10 Hz repetition rate. The dark current during the operation of the RF gun has been found to be...
SLAC’s LCLS-II is advancing towards MHz repetition rate attosecond X-ray pulses, creating opportunities to optimize X-ray generation through machine-driven controls and diagnostics via start-to-end simulation. Advanced laser shaping and upconversion techniques at the photoinjector, such as spatial light modulator-based pre-amplifier pulse shaping linked to nonlinear methods such as...
The Novosibirsk Free Electron Laser (NovoFEL) is a facility that consists of three free electron laser (FEL) systems installed on different parts of the Energy Recovery Linac (ERL). These three FELs share the same acceleration system, which enables the generation of high average electron current, typically around 10 mA. Precise measurement of the electron beam parameters is essential for...
A muon linear accelerator is under development at J-PARC for precise measurement of the muon anomalous magnetic moment (g-2) and electric dipole moment (EDM). A disk-and-washer (DAW) structure is employed to accelerate muons from 30% of the speed of light (kinetic energy = 4 MeV) to 70% (40 MeV) at 1296 MHz. The muon DAW consists of tanks accelerating the muons and bridge couplers that couple...
The degree of spin-polarization of electrons photoemitted from unstrained, room-temperature GaAs is usually significantly less than the theoretical maximum of 50%. However, it has been experimentally observed that the degree of electron spin polarization can be increased and even exceed the theoretical maximum when the sample is cooled to low temperatures and in strained-lattice samples. The...
The Muon Collider is a proposed future accelerator for very high energy muon collision. Since muons are heavier than electrons, the synchrotron radiation is negligible at this high energy, allowing to build a compact machine able to deliver Multi-TeV c.o.m. energy collisions, enabling precision measurements of the Standard Model quantities and search for new physics. A challenge of a muon beam...
The accurate assessment of beam quality is the most important aspect in the irradiation facilities operation such as IRRAD at CERN. The Beam Profile Monitor (BPM) sensor system developed for the high-intensity proton beam at IRRAD features minimal particle interaction, improved radiation hardness and higher sensitivity and sampling rate than previous systems. It provides a wealth of...
MedAustron, a synchrotron-based ion therapy centre in Austria, is focused on enhancing cancer treatment performance. A key improvement opportunity lies in the regulation of the main ring bending dipoles, which currently require time-consuming procedures to ensure reproducibility and reliability of the associated magnetic fields (B-Fields). Other therapy centres globally address this through a...
In order to explore an efficient and accurate method for measuring the magnetic field information of accelerator magnets, this paper used the stretched wire system to measure a quadrupole magnet prototype of Hefei Advanced Light Source. In the measurement process, the integral field of the magnet at multiple points was first measured to calculate the magnetic center and multipole components of...
In this study, we investigated the possibility of using a passive dielectric-lined waveguide structure on slice energy spread measurement of femtosecond electron beam. Such diagnostic setup for a 25 MeV electron beam with a duration of a few hundred femtoseconds is simulated using IMPACT-T. The DLW acts as a passive streaker by generating traverse wakefields that deflect the electron bunch....
The radiation damping time is a crucial parameter that depends on the overall magnetic structure of the accelerator. Accurate measurement of this damping time can provide insights into the fidelity of the accelerator model by allowing for a comparison with calculated damping time values. In this study, we present a series of measurements of radiation damping times at the VEPP-4M and VEPP-2000...
The transition from 3rd to 4th generation synchrotron light sources can primarily be characterized by a significant reduction in horizontal emittance. This enables a nearly uniform transverse X-ray beam profile and a brilliance that approaches the diffraction limit. A consequence of the upgrade to Diffraction Limited Storage Rings (DLSRs) is that the traditional emittance measurement...
This work presents techniques for non-invasive transverse profile measurements of high-intensity proton beams using an Electron Beam Profile Scanner (EBPS). The EBPS utilizes low-energy electrons as a probe to analyze the transverse size of proton beams, allowing for potential analysis on a single-bunch basis. Recent upgrades to the Fermilab Main Injector have enhanced beam power on target to...
The injector system of SIRIUS, the brazilian 4th generation synchrotron light source, currently operates with non-ideal injection efficiencies, which may impose limits to future top-up operation modes. Within this context, diagnostic techniques to access beam quality in the injector are essential tools for optimizations. In this work, the MENT algorithm was implemented for the reconstruction...
Charged particle bunches traversing cavity-like discontinuities in the beam pipe at relativistic velocities excite electromagnetic resonant modes that can detrimentally affect the dynamics of trailing bunches. This beam-cavity interaction, characterized in the frequency domain through the concept of beam-coupling impedance, poses significant challenges for beam stability and performance in...
SuperKEKB, located at KEK, is a second generation B-factory, providing beam to the Belle-II experiment. Optics design and simulation of SuperKEKB were previously performed using the optics code SAD, developed at KEK. In this paper, we present a new model of SuperKEKB using the tracking code Xsuite, developed at CERN. An alternative strategy for modelling the interaction region, with...
The ASU cryogenically cooled DC electron gun represents a state-of-the-art platform for testing novel photocathodes at room and cryogenic temperatures. The key electron beam diagnostic tool of this setup is the four-dimensional (4D) phase space reconstruction using the pinhole scan technique. In this work, we use the 4D phase space measurement to extract the Mean Transverse Energy (MTE)...
This study presents a multi-objective optimization scheme for ring cyclotron RF cavities, leveraging a neural network ensemble surrogate model. The cavity geometry is parameterized using Non-Uniform Rational B-Splines (NURBS), with control points and weights as design parameters. To reduce the computational cost of direct eigenmode simulations, an ensemble of neural networks trained using...
Superconducting(SC) radio-frequency(RF) quadrupole (RFQ) integrates the high efficiency of SC technology with the strong focusing and stable acceleration capabilities of RFQ .It is a critical development in next-generation high-performance accelerators.In this study, we present the multi-physics analysis results of a SC RFQ test cavity operating at a frequency of 280 MHz. This test cavity is...
Aperture measurements at the Large Hadron Collider (LHC) are routine procedures conducted during the early stages of beam commissioning, prior to the injection of high-intensity beams. This is to ensure that the aperture, defining the clearance for the circulating beams, is protected by the LHC collimation system. Local aperture measurements are performed to probe the available aperture at...
The Landau states of electrons with orbital angular momentum in magnetic fields are important in the quantum theories of synchrotron radiation at storage rings and in many other areas. In realistic scenarios, electrons are often born inside the field or injected from a field-free region, requiring nonstationary quantum states to account for boundary or initial conditions. This study presents...
We recently commissioned the Next GenerAtion Photocathode Laser system (NEPAL) in Hamburg’s XFEL facilities (FLASH and EuXFEL) and at DESY’s Photoinjector Test Facility (PITZ). The system delivers deep UV pulse trains up to 1 ms long at repetition rates as high as 4.5 MHz, with temporal and spatial shaping capabilities and individual amplitude control for bunch charge manipulation. The shaping...
Abstract—A SCILAB Xcos model, developed using SCILAB software version 6.1.1, was implemented to simulate the on-axis radiation intensity of a helical undulator, (undulator parameter= 1, undulator wavelength 5cm, number of periods= 10, device length 0.6 m) with an electron beam (1, 2, & 3 GeV) and beam current as Ib = 3–6 × 10⁻⁶ Ampere. A numerical approach is utilized to perform the undulator...
The Large Hadron Collider (LHC) features a collimation system that protects the machine against beam losses that may induce the loss of superconductivity in some exposed lattice magnets. Thus, optimal cleaning performance must be ensured at all times. The collimation system encompasses more than 100 collimators whose settings are organised in a well-defined transverse multi-stage hierarchy. A...
At CERN’s Low Energy Ion Ring (LEIR), high beam intensities are achieved through phase space painting with up to eight multi-turn injections from the linear accelerator Linac3. After each injection, the beam is cooled and stacked in longitudinal phase space using an electron cooler. During beam operation, key parameters such as RF cavity phases in the linac, the LEIR electron cooler gun...
Additive manufacturing is a now-powerful tool for the rapid prototyping and manufacturing of complex geometries. A proof-of-concept 433 MHz IH-DTL cavity was constructed for direct additive manufacturing of linear accelerator components. The CFD analysis of the initially designed cooling for the drift tube revealed a design with insufficient heat dissipation; this can lead to thermal...
Plasma Wakefield Acceleration (PWFA) is a method of accelerating charged particles using a plasma. It has the potential to produce exceptionally large accelerating gradients on the order of 10’s of GeV/m. The FACET-II test facility accelerates pairs of 10 GeV electron bunches to study the PWFA process—a drive bunch to produce a wake in the plasma in a lithium-ion oven, and a witness bunch to...
The Korea-4GSR is a next-generation diffraction-limited light source designed to provide beam brightness up to 100 times greater than existing facilities. Chromatic aberrations from strong focusing fields in quadrupoles are corrected using sextupoles and octupoles. However, these sextupoles and octupoles introduce nonlinear effects, causing electrons to follow nonlinear trajectories,...
A recent simulation study demonstrated the potential to achieve high 4D-emittance using an emittance exchange (EEX) beamline integrated within a photoinjector. This EEX beamline enabled to achieve the final normalized longitudinal emittance of 0.44 micron, which corresponds to rms bunch length of 7micron and energy spread of 32keV. These results are noteworthy for a 60-MeV photoinjector...
The increased beam intensity during the high lumionsity LHC era is expected to impose tight margins on the operation of the LHC RF system. The larger momentum spread from the injectors together with twice the bunch charge requires a higher RF voltage at injection to avoid beam losses. However, the peak RF power due to the increased beam loading must be kept below the saturation level of the...
Collimators are used to minimize losses and to remove particles that would otherwise get lost downstream and irradiate the machine. Finding the optimal jaw positions is time consuming and with the upstream beam properties changing, the collimation settings would need to be readjusted each time. Therefore, a method to optimize collimator positions and to operate them at full capacity in a short...
Initial experimental investigations of transverse beam splitting, carried out at the CERN Proton Synchrotron, have demonstrated that transverse feedback is highly effective in controlling the characteristics of the transversally split beam. The feedback notably improves the intensity distribution among the beamlets and the emittance of the core, which is the portion of the beam remaining near...
The surface muon beamline at J-PARC provides high-intensity muon beams that are essential for advanced materials science research, particularly in techniques such as muon spin rotation/relaxation (μSR). However, positron contamination in the beam poses a significant challenge by introducing background noise that affects the measurement precision. Therefore, achieving high-purity muon beams is...
China Spallation Neutron Source (CSNS) accelerator complex will employ a new superconducting accelerating section to provide high beam power. To prevent contamination of the superconducting cavity surface caused by sputtering, shedding, or melting of medium materials during interceptive beam measurements, the second phase of the China Spallation Neutron Source (CSNS) superconducting linac...
The National Synchrotron Radiation Laboratory is constructing a 2.2 GeV diffraction-limited storage ring, the Hefei Advanced Light Facility (HALF), using the modified hybrid 6BA lattice, which consists of a total of 20 cells. The synchrotron radiation primarily covers the vacuum ultraviolet (VUV) to soft X-ray bands. To extend the photon energy into the hard X-ray range, two 0.9 T...
A Terahertz (THz) transition radiation monitor, as part of a Bunch compression monitor (BCM), is implemented for longitudinal bunch diagnostics at FELs such as ELBE, FLASH, or EuXFEL. Pulse energy measurements are typically carried out after each bunch compressor stage using coherent diffraction radiation (CDR) in the THz domain and pyroelectric detectors. For higher repetition rates in the...
High-current and low-energy storage ring is an essential part of accelerator for industrial application. However, high intensity poses great challenge to beam stability through collective effects, which can be exacerbated at low energy. In this paper, we present a preliminary study on various collective effects in an application-oriented storage ring. The classical theory is reviewed, and...
Precise measurement of an electron bunch’s longitudinal profile is critical for wakefield accelerators as shaped electron bunches can improve transformer ratios in collinear wakefield acceleration. Electro-Optic sampling of terahertz (THz) radiation from the bunch is one of the most attractive approaches to provide a view into the structure of a relativistic electron bunch due to its...
Gamma-ray induced nuclear physics experiments rely on good signal-to-noise ratio, requiring accurate rejection of detector background. One source of this background is the interaction of cosmic rays with nuclear detectors. The Duke High Intensity Gamma-ray Source (HIGS) is typically operated in quasi-CW mode, requiring background measurements to be conducted independently of data production...
This study presents the development and implementation of a reinforcement learning-based algorithm for real-time luminosity tuning in collider experiments. The algorithm is initially pretrained on historical collider data and subsequently fine-tuned online during experiments. By analyzing accelerator measurements collected over several seconds, the model adjusts the magnetic structure to...
Simultaneous irradiation with mixed helium and carbon ions is being proposed for online range verification in carbon radiotherapy. In 2024, a mixed $^4$He$^{2+}$ and $^{12}$C$^{6+}$ beam, generated by sequential injection of helium and carbon ions into the synchrotron, was extracted successfully for the first time at the MedAustron ion beam therapy and research center. This double injection...
The VEPP-2000 collider is a compact machine, which uses the round-beam concept to achieve high luminosity. Its compact size (24 m in circumference) limits the free space between the magnetic elements. Only 4 BPMs are installed in the ring with large phase advance between them (~2 pi). The key to improve its luminosity is to reduce the power of resonances. The implementing of the RDT...
The Quadrupole Resonator (QPR), originally developed at CERN, is a dedicated radio-frequency characterization equipment for evaluating superconducting material. It employs the calorimetric compensation technique and has a surface resistance resolution of less than 1 nOhm, operaing over a wide range of parameters, such as tem-peratures, resonant frequencies and magnetic fields. As a part of R&D...
The Super Tau-Charm Facility (STCF) is a new generation of electron-positron colliders being planned with a design center of mass energy of 2-7 GeV. In the concept design, the positrons produced by electron targeting are accelerated to an energy of 200MeV by three large-aperture accelerating structures, and then to 3.5GeV by several conventional accelerating structures. The aperture of...
RF breakdown studies are crucial for machines relying on high-gradient, normal-conducting RF accelerating cavities. Searches for breakdown precursors in high-gradient test-stand data have been conducted and highlight the need for a new diagnostic with improved temporal response. Emission of Cherenkov light in optical fibers has been identified as one such diagnostic**, which occurs when...
Previous works on reconstructing the 4D phase space using tomography require optimal selection of projection views to achieve accurate reconstruction. In 2D reconstruction, the process is straightforward, as an object can be evenly sampled by dividing the angles evenly. However, extending this concept from 2D to 4D is not intuitive. This work demonstrates that quaternions can be used to more...
A novel service-based EPICS and new front-end data acquisition method based on a high-availability Kubernetes cluster built on the Proxmox VE platform are proposed in this paper to enhance the performance and stability of the data acquisition system. By deploying EPICS services on the Kubernetes cluster, a new efficient front-end data processing and acquisition method is realized. The data...
TWOCRYST is a machine test designed to demonstrate the feasibility of an in-vacuum fixed-target experiment for the first direct measurement of the magnetic and electric dipole moments of short-lived charm baryons. This setup exploits crystal channeling using two bent crystals. The first one is similar to the existing crystals used in the LHC for beam collimation, deflecting the beam halo...
THz technology being a highly growing and potent field, finds use in a wide range of research applications. Delhi Light Source (DLS) at IUAC, New Delhi is at final stage of commissioning to produce intense and coherent THz radiation based on pre-bunched Free Electron Laser principle. As an addition to the narrowband undulator radiation, broadband Coherent Transition Radiation (CTR) will also...
A circular waveguide lined with a thin dielectric layer enables electron bunches propagating within the structure to radiate light in the (sub-)THz regime. In this work, we perform simulations of low-energy electron beams traversing extended waveguides to analyze the dynamics of beam bunching and lasing within the structure. By exploring the free-electron laser (FEL) process in this context,...
We present an electromagnetic characterization and beam dynamics study of nanostructured plasmonic copper photocathodes for electron gun applications. The study concentrates on photocathodes operated at ultraviolet and infrared wavelengths. Various types of nanopatterns are explored in order to understand how different geometrical parameters affect light reflectance. Optimized nanostructure...
The electron-positron Future Circular Collider (FCC-ee) is a proposed high-energy lepton collider that aims to reach unprecedented luminosity and precision in the measurement of fundamental particles. To fully profit of such performance, it is crucial to keep detector backgrounds under control and operate the machine safely. Due to the high stored beam energy and to a number of complex...
Laser Wakefield Accelerators (LWFA) offer a promising solution for producing high-energy electron beams in compact setups. Beyond obtaining the required energy, the beam quality (emittance, energy spread, intensity) must also be optimized for LWFA to be considered an alternative to conventional accelerators. Achieving precise control of the transverse beam dynamics is one of the key...
Novel acceleration schemes aim to address the need for higher acceleration gradients which enable to minimise the size and costs of particle accelerators. One of these novel accelerator schemes is the dielectric wakefield acceleration (DWA), where an electron bunch is accelerated by the longitudinal wakefields generated within a dielectric lined waveguide by a leading drive bunch with higher...
In ultrafast electron diffraction experiments, the scattering cross-section, q-range, and space-charge effects are critically influenced by the electron beam energy, which is constrained by the high-voltage breakdown. By integrating a 100 kV DC electron gun with a 3 GHz radiofrequency cavity powered with a 400 W amplifier, we demonstrate a net energy gain of up to 31 keV. Here we present...
We have started single electron storage experiments since 2021 at the UVSOR-Ⅲ storage ring with the aim of conducting fundamental research on electromagnetic radiation. At BL1U, which is a beamline dedicated to light source developments, we extracted undulator light in the UV wavelength range into the air and observed its intensity by a photomultiplier tube, as decreasing the electron beam...
The information on phase space in all six dimensions is required for various accelerator experiments. We developed an algorithm based on Convolutional Neural Network (CNN) that can be used instead of the traditional back projection techniques because it is less computationally intensive and has a simple architecture. Our method has shown consistency with the simulation, and we plan to validate...
Transmission Electron Microscopes (TEM) require high voltage DC electron sources, which can quickly grow in size and cost at the higher energies required for standard TEM imaging. We present the progress on a low cost, compact solid-state-driven RF linac to replace high power electron guns in micro-crystal electron diffraction setups. The system accelerates electrons to 50 keV electrons with a...
Highly polarized MeV gamma rays, produced by Laser Compton Scattered (LCS) of a polarized laser with an electron beam, offer a unique probe for basic and applied physics research. As the polarization characteristics of these gamma rays vary with the position of the beam cross section, it is essential to understand the polarization properties when using polarized gamma rays * . However,...
Recently, two SIRIUS beamlines, EMA and PAINEIRA, received their definitive insertion devices (IDs). Both IDs are in-vacuum devices (IVUs), the first of this kind at SIRIUS. Due to the proximity of the IVU cassettes to the electron beam, the spectrum emitted by these devices is highly sensitive to misalignments of the ID magnetic center. Such misalignments can result in photon flux losses,...
Resonant slow extraction is routinely used to provide ion beams to various users. At GSI SIS18, two extraction methods are implemented: quadrupole-driven and Radio Frequency Knock Out (RF-KO) extraction. In either case, delivering a defined beam intensity (spill) without fluctuations or drifts is desired for an efficient beam usage. The Spill Optimization System (SOS) was developed to address...
Non-evaporable Getter (NEG) coating is a breakthrough technology wherein the inner walls of a vacuum chamber are coated with a material that functions as a vacuum pump. This technology is expected to gain widespread adoption across various fields in the future. However, the current coating method, originally developed for long beam ducts, is not adaptable to a wide range of vacuum chamber...
The superconducting cyclotron SC240 is used to accelerate proton beams to 240 MeV for proton therapy. The SC240 is an isochronous 4 sectors compact cyclotron with a central magnetic field of 2.5 T. Particles acceleration is performed under the second harmonic mode of the radio-frequency (RF) system, consisting of two independent cavities located in the cyclotron valleys. Block on the chimney...
The study of beam-cavity interaction is an essential step towards achieving the design objectives of high-intensity storage rings, particularly in the rapidly advancing fourth generation of synchrotron light sources, which rely on the strategy of bunch lengthening with harmonic cavities. Assessing the effectiveness of harmonic cavities typically requires self-consistently solving bunch...
This work examines the dominant coherent head-tail type (< x-z >) instabilities in the vertical plane of the FCC-ee collider, focusing on a mode analysis method with the Circulant Matrix Model (CMM) to assess instability mechanisms under the influence of beam-beam effects and transverse wakefields. While the impact of vertical plane instabilities have been already studied, different...
We propose a phase jump method to improve the electron beam conversion efficiency in FEL oscillator. A fast phase shifter is put between two undulator segments to kick the phase of the electron beam at saturation. The theoretical and simulation results are given based on FELiChEM which is built in Hefei. They indicate that a phase jump value of approximately π at saturation can significantly...
The fast polarization switching of undulator radiation has attracted more and more attention in recent years. Recently, a new method has been proposed for fast polarization switching up to kilohertz of undulator radiation by using magnetic field modulation generated from low-current electromagnetic coils. Through fast switching the power of coils, the radiation spectra of two undulators can be...
The traditional APPLE-KNOT undulator forms composite magnetic fields by superimposing APPLE fields and KNOT fields with the period ratio of 2:3. The APPLE field serves as the main component to approximate the target photon energy, while the KNOT field acts as an additional component to transversely deflect the electron beam away from axis. Variable polarization states can be generated with a...
Cs-Sb compound thin-film photocathodes are an excellent candidate to produce bright electron beams for use in various accelerator applications. Despite the virtues of these photocathodes being known, the mechanics that govern their promising photoemission are not well-understood. Crystalline and other material properties affect the quantum efficiency (QE) as well as mean transverse energy...
The all-optical synchronization system used in many X-ray free-electron laser facilities (XFELs) relies on electro-optical bunch arrival-time monitors (EO-BAM) for measuring the single bunch arrival-time with regards to an optical reference. An upgrade of the established EO-BAM is intended to achieve a sensitivity that enables stable operation with bunches down to charges of 1 pC or...
A 162.5 MHz, optimal beta = 0.19 pure niobium half-wave resonator (HWR) called HWR019 for the superconducting driver linac of the China initiative Accelerator-Driven subcritical System (CiADS) has been designed and analyzed at the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). The linac requires 24 HWR019s to accelerate protons from 6.8 MeV to 45 MeV. This paper mainly...
Acceleration by the wakefield in the plasma can provide compact sources of relativistic electron beams of high brightness. Free electron lasers and particle colliders, using plasma wakefield accelerators, require high quality bunches with predictable profile. Previous studies showed that the resonant sequence of electron bunches appears to be unstable due to the destruction of the bunches. In...
Alkali antimonide photocathodes exhibit high efficacy as photoemissive materials in electron sources. This proceeding explores the fabrication of thin, ordered films of sodium potassium antimonide via molecular-beam epitaxy (MBE) at the PHotocathode Epitaxy Beam Experiments (PHOEBE) laboratory at Cornell University. Utilizing a sequential deposition technique, the photocathodes are...
THz sources are typically very limited in power, making high-power sources scarce. One of the most promising THz sources are the Free Electron Lasers (FELs), which can generate high-power THz radiation using an undulator structure. Undulator radiation is an incoherent synchrotron spontaneous emission whose energy is proportional to the number of particles in the beam (𝑁). By longitudinally...
A uniformly moving electron passing through a slab induces electromagnetic
emission known as transition radiation. The generated rays propagate inside
the slab and undergo multiple reflections off the slab boundary. We employ the polarization current method in order to derive the reflectionless
solution for an observed radiation intensity and compare it with that of Pafomov
which accounts...
The synchrotron radiation generated by storage rings offers numerous advantages, including high stability, a broad photon energy range, and the capacity to support multiple users simultaneously. However, one notable limitation is its poor radiation coherence. Achieving coherent harmonic generation (CHG) in storage rings would not only significantly enhance the coherence of the emitted light...
The field of Free-Electron Lasers (FELs) has matured, with advancements prioritizing high repetition rates, full coherence, and an expanded wavelength spectrum. This paper details the establishment of a high-repetition-rate Infrared Terahertz (IR-THz) Free-Electron Laser (FEL) facility at the Hefei Comprehensive National Science Center. This facility is strategically integrated with the...
This study addresses the insufficient focusing force in solenoid focusing devices for low-energy electron accelerators, which leads to beam spot precision issues. A tunable double-ring permanent magnet focusing device based on the Halbach structure is proposed. The use of octagonal magnets replaces traditional sector magnets, avoiding the issue of differing magnetization directions. The...
Multi-bunch instabilities, often driven by narrowband impedance sources such as higher-order modes, present significant intensity limitations in synchrotrons. One approach to mitigate these instabilities is applying a double harmonic radio frequency (RF) system, which can increase the intensity threshold by enlarging the synchrotron frequency spread. In this study, intensity thresholds are...
The collective effects observed in storage rings with high-intensity beams are numerous and diverse. One such effect is that of periodic beam loading of accelerating RF cavities. This effect is contingent upon the impedance of the fundamental mode of the RF cavities and the mode of filling pattern. In a multitude of configurations, the periodic beam loading effect in storage rings leads to a...
The results of Run 24 experiments at Relativistic Heavy Ion Collider (RHIC) for improving luminosity using optics tuning are presented in this study. In the first experiment, MADx matching was used to output magnet strengths corresponding to specific s star movements around Interaction Region 8 (IR8). The corresponding Zero Degree Calorimeter (ZDC) signal was measured in place of luminosity,...
Superconducting radio-frequency (SRF) electron linear accelerators (e-linacs) provide significant advantages over conventional room-temperature accelerators, especially in their capacity to accelerate high-intensity continuous-wave (CW) beams. Recently, the first liquid helium-free (LHe-free) Nb₃Sn SRF cavity was successfully operated at the Institute of Modern Physics of the Chinese Academy...
Ongoing conceptual studies for a 10TeV muon collider identified rapid cycling synchrotrons as major engineering challenge. Due to the muon’s short lifetime of only 2.2µs at rest, normal-conducting bending magnets with field rise rates of well beyond 1kT/s are indispensable to support accordingly fast acceleration cycles. Energies of 100MJ will be interchanged between magnets and capacitor...
Plasma wakefield acceleration in the filament regime can provide wakefields suitable for high-gradient, high-quality positron acceleration while maintaining stability. However, the energy that can be extracted by the positrons is limited. Recent works have proposed accelerating a supplementary electron recovery bunch along with the positron bunch to extract more energy from the wake and...
Determining Yukawa couplings of the Higgs boson is one of the most fundamental and outstanding measurements since its discovery. The FCC-ee, owing to its exceptionally high-integrated luminosity, offers the unique opportunity to measure the electron Yukawa coupling through s-channel Higgs production at 125 GeV centre-of-mass (CM) energy, provided that the CM energy spread can be reduced from...
Single crystal alkali antimonide photocathodes have been shown to produce brighter beams than their polycrystalline counterparts. These single crystal semiconductors require a lattice matched substrate to be grown, but current INFN plugs lack the capability for this growth. To relieve this issue, we modified the INFN plug to hold a disk 1cm in diameter. This allows for studies of a wide range...
Optical frequency comb (OFC) technology provides precise measurement tools for optical frequencies, leading to revolutionary changes in the field of optics.OFCs consist of a series of uniformly spaced spectral lines resembling the teeth of a comb, and they have found widespread applications in timing, precision spectroscopy, and fundamental physics.Extending this technology into the EUV to...
