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The 16th International Particle Accelerator Conferece at Taipei, Taiwan
The Taiwan Photon Source has been in routine operation at 500 mA since the last season of 2022, utilizing two superconducting cavities and a bunch by bunch feedback system, fast orbit feedback system, along with many technical efforts. The operation of both the Taiwan Photon Source (TPS) maintains its high reliability and availability. The mean time between failures is more than 190 hours with an availability greater than 98.9% for both sources in 2023. With newly developed cryogenic permanent magnet undulators, IVUs, and EPUs, balancing the needs of both soft X-ray and hard X-ray users.
Many challenges have been encountered on the road to achieving a beam current of 500 mA, primarily due to the short bunch length of 16 ps at the TPS storage ring. Impedance issues occur at the strip kicker, undulators with in-vacuum type, and BPMs. The details will be presented.
Ongoing technical development focuses on in-vacuum nonlinear kickers to minimize electron orbit perturbations during top-up injection. Lamda cavity to enlogate the bunch length. Furthermore, more aggressive upgrade or expansion plans for light source development are steadily under discussion to meet the needs of the thriving synchrotron radiation users in Taiwan.
The Radioactive Isotope Beam Factory (RIBF) of RIKEN is a cyclotron-based heavy ion accelerator facility, which can accelerate heavy ions including uranium up to 345 MeV/u using an accelerator complex with a K2600-MeV Superconducting Ring Cyclotron (SRC) in the last stage to produce rare isotope beams in an in-flight technique. In the 15 years of developments the intensity and stability of the heavy-ion beams have been significantly improved. The core experimental instrumentations, such as the Rare RI Ring, are now in operation, and further results are expected in the future. This presentation will discuss the various technological developments that have been made since the start of RIBF acceleration and will provide future directions.
Review of nonlinear resonances in accelerators and storage rings; including a discussion of chaos, particle diffusion and dynamic aperture
Achieving high-gradient acceleration is critical to enabling future linear colliders, free-electron lasers, and compact accelerator applications. Pioneered by the Argonne Wakefield Accelerator (AWA) group, short-pulse SWFA (structure wakefield accelerator) technology has shown remarkable promise in surpassing the long-standing barrier of ~100 MV/m in X-band normal conducting structures. Recent experiments have demonstrated the feasibility of this approach, with the gradient exceeding 300 MV/m in a variety of X-band accelerating structures and an X-band photogun. Experimental results indicate that the well-known empirical scaling law to estimate the RF breakdown rate (BDR ~E^30*t^5) may be too conservative when the RF pulse durations below 10 ns. A conceptual design of ultracompact XFEL based on the short pulse acceleration will be presented.
Liquid metal technology is key to the next-generation high-power hadron facilities. Following early R&D collaboration between Argonne National Laboratory and Michigan State University, FRIB pioneered on the technology of thin-film liquid lithium and is the first in the world applying such technology in accelerator operations. FRIB used liquid-lithium film for the charge stripping of high-power heavy-ion beams, enabling FRIB to achieve world’s highest power uranium beam on target.
Liquid lithium technology has been successfully developed and applied for FRIB operations, offering a superior choice for charge stripping of high-power heavy ion beams including uranium. Valuable experience has been gained in the performance and maintenance. This talk focuses on operational experience, lessons learned and future improvements.
In this talk, ILC accelerator IDT development status will be given, where positron source, final focus system ATF3, SRF cavity and cryomodule, civil engineering design, green ILC technologies, etc. will be presented in detail.
A Muon Collider (MC) offers unique potential for reaching the 10 TeV center-of-mass energy regime. The most recent updates to both the European and US strategies for particle physics emphasize the importance of exploring this technology as a path to enable the next generation of energy frontier discoveries. Substantial updates to the baseline design concept have now been implemented by the International Muon Collider Collaboration. An overview of progress towards establishing the baseline design of the 10 TeV machine and delivering a full conceptual design report for this novel collider approach is presented.
The utilization of permanent magnets in the design of accelerator magnets has witnessed a surge in prominence, particularly within the realm of advanced light sources. Following pioneering initiatives at SIRIUS and ESRF-EBS, current projects are increasingly embracing permanent magnet technology. Notably, in the case of SLS2.0, over 30% of the magnets in the new storage ring are powered with permanent magnets. Permanent magnets offer manifold advantages, including compactness, much simpler requirements in terms of services (such as power supplies, cables, and cooling systems), and reduced operational costs. Nonetheless, they also present significant challenges that demand careful consideration. In this study, the author provides an overview of permanent magnet implementations across various projects and delves into a detailed analysis of the Swiss Light Source upgrade.
It is about “Development for Various Application at Compact ERL as a high-current CW SRF linac in KEK”. As an introduction, the author will talk about the merit of the superconducting RF (SRF) cavity and also talk about our applied research based on Compact ERL (cERL) in KEK, which uses the Nb superconducting cavity and can make energy recovery operation. The cERL's characteristic using the high-current beam has the variety of applications; industrial applications using high-intensity terahertz light and mid-infrared FEL (free-electron laser). In addition, the high current CW beam irradiation was conducted for basic research on domestic production of nuclear medicine, strengthening of asphalt, and the highly efficient production of nanocellulose from wood in cERL. After talking these applications of cERL, next we will talk about “Future plan for applied research using superconducting accelerators”. One is the EUV-FEL light source development for EUV-lithography and the other is the development of compact superconducting RF accelerator based on Nb3Sn for high-power beam irradiation.
Safety is one of the main concerns in accelerator society. The key FRIB strategies and experience can be shared, leading to the successful FRIB operations with no safety-related incidents and meeting stringent standard in a university area.
Personnel protection and machine protection are key to high power frontier facilities like FRIB. For a facility built in the middle of university campus with heavy ion beam power being ramped up order of magnitude higher than the current record, stringent engineered and administrative controls and state-of-the-art technologies are needed to safeguard commissioning, operations, and upgrades.
The pursuit of optimal beam quality and stability in linear accelerators (Linacs) stands as a cornerstone of accelerator physics. However, the presence of High Order Modes (HOMs) within Linacs, particularly in the context of energy recovery (ERLs), presents formidable challenges to beam quality and stability. In response to this challenge, the development of the Compact HOMEN (High Order Mode Evolution based on Energy budget) model has emerged, providing precise prediction and analysis of HOM effects on beam dynamics within superconducting cavities. This model facilitates meticulous optimization strategies, guiding researchers towards unprecedented advancements in high-brightness accelerated electron beam technology. By comprehensively understanding and managing HOMs, Linacs can achieve enhanced performance and efficiency, crucial for a myriad of scientific and industrial applications.
Through this study, we underscore the constraints posed by high currents and high repetition rate to ensure an optimal energy recuperation. Our findings not only deepen the understanding of ERL facilities but also underscore their transformative potential in shaping the forefront of accelerator technology.
This talk will review high intensity beam production by highly-charged ECR ion sources operating at microwave frequency 24-28 GHz and the related new technology development. To further improve beam intensity for higher charge state heavy ion beams, the world First fourth generation ECR ion source (named as FECR) with microwave frequency 45 GHz is being developed at IMP. After 8 years development, it is expected to start beam commissioning by May 2024. This talk will present the first beam commissioning results of FECR.
The recent P5 Report calls for a 10 TeV parton center-of-mass (pCM) collider, for which advanced wakefield accelerators are a candidate technology. Design studies are being developed including particle sources, damping rings, and linacs based on plasma and structure-based wakefield accelerators. Compact Beam Delivery Systems may be possible using plasma lenses, requiring understanding of their impact on the design of the Machine-Detector Interface, and optimization of detectors for 10 TeV e+e- and γγ collisions. The results of the design study will define the necessary technology demonstrations to be performed. There are synergies between the design of a 10 TeV linear collider and Higgs Factory linear colliders. This study is hence developing tools and innovations that can be broadly useful to the collider community, and interaction among efforts is important.
The shortening of the FEL pulse length is an important subject, and especially reducing the FEL pulse length down to a few-cycle duration is a great challenge. However, there exists a theoretical limit that disturbs the realization of few-cycle FELs, which is known as the slippage effect. Recently, the author proposed a novel idea to overcome this difficulty and experimentally demonstrated it [1]. This talk is expected to review its fundamental mechanism and report the results of the demonstration experiments, together with perspectives of few-cycle attosecond pulses that become available with this concept.
[1] T. Tanaka et al., Phys. Rev. Lett. 131, 145001 (2023)
SPS-II is the forth generation storage ring project in South East Asia.
Speaker should give the overview of the SPS-II.
The recent progress and update on the project will be given.
Development programs for prototypes will be covered.
Carbon ion therapy is gaining popularity due to its unique physical and radiobiological properties, such as a lower oxygen enhancement ratio (OER) than photon and proton therapy, indicating that efficacy is not limited by hypoxic tumor microenvironments. It also has a Its superior anticancer effect on hypoxic tumor cells, which are resistant to chemotherapy, radiotherapy, and immunotherapy. It is thus used to treat a wide range of cancers and increasingly being used to treat recurrent disease. TVGH is a national medical facility committed to protecting public health and upholding the highest medical standards. Given that cancer is Taiwan's leading cause of death, accounting for one-third of our hospitalized patients, we have spent decades researching and implementing cutting-edge anticancer treatments. As well as to complete the anticancer treatment spectrum in Taiwan, TVGH has established a carbon ion therapy facility of synchrotron accelerator type. Its construction began in 2019 and was completed in a record-breaking 15 months. After twenty months of equipment installation and verification, TVGH became the world's fourteenth and Taiwan’s only carbon ion therapy facility. Since the opening of this carbon ion therapy facility in May 2023, TVGH has treated nearly 200 patients, more than 90% of whom have pancreatic, prostate, liver, or lung cancer. Although TVGH has only been monitoring these patients for less than one year, numerous favorable results have been observed.
This contribution will detail how the development of accelerator sources and linacs for particle physics has found applications in medical and industrial environments. In particular for electron therapy, ion therapy and PIXE (Proton Induced X-ray Emission).
This work received the PRAB 2023 DPB and PRAB Ernest Courant Outstanding Paper Recognition.
https://journals.aps.org/prab/abstract/10.1103/PhysRevAccelBeams.24.093201
Paper abstract:
In this paper, we present an experimental demonstration of the high-gradient operation of an X-band, 11.424 GHz, 20-cells linear accelerator (linac) operating at a liquid nitrogen temperature of 77 K. The tested linac was previously processed and tested at room temperature. Low-temperature operation increases the yield strength of the accelerator material and reduces surface resistance, hence a great reduction in cyclic fatigue could be achieved resulting in a large reduction in breakdown rates compared to room-temperature operation. Furthermore, temperature reduction increases the intrinsic quality factor of the accelerating cavities, and consequently, the shunt impedance leading to increased rf-to-beam efficiency and beam loading capabilities. We verified the enhanced accelerating parameters of the tested accelerator at cryogenic temperature using different measurements including electron beam acceleration up to a gradient of 150 MV/m, corresponding to a peak surface electric field of 375bMV/m. We also measured the breakdown rates in the tested structure showing a reduction of 2 orders of magnitude compared to their values at room temperature for the same accelerating gradient.
The KEK injector linac injects high-charge electron and positron beams
into the high-energy-ring and low-energy-ring of SuperKEKB
respectively. The linac also injects electron beams to the two light
source rings, PF ring andPF-AR. We operate simultaneous top-up
injections into the four rings by using many pulsed magnets. We have
been upgrading the linac to attain the higher-quality beam injections
for the SuperKEKB rings. In the summer of 2023, large-aperture
quadrupole pulsed magnets have been newly installed upstream of the
linac and driven by large-current pulse power supplies at markedly
high electric efficiency. These new magnets bring the pulse-by-pulse
optics changing to provide the high-quality beams. In order to cope
with the complex beam injections to the four rings, we have introduced
the automatic adjustment system by using machine-learning. The system
surpasses human skill in beam adjustment and has resulted in
significant increases in the amount of beam charge and beam
transmission.
We will report on the results of these upgrades.
The long term sustainability of future accelerators is now a crucial problem for our community. Many groups and collaborations are actively working in this area (e.g. European projects included IFAST and iSAS, RUEDI (STFC) has recently published a case study for the project lifecycle, Centre of Excellence in Sustainable Accelerators is now being vigorously pursued in the UK with CERN backing, European LDG working group, etc). This talk will review the wider community efforts and highlight where good progress is being made and where future efforts are planned or required.
EM field around a relativistically accelerated charged particle is known to squeezed longitudinally, which is called Lorentz contraction. This behavior is well-believed and no inconsistent phenomena have been found so far. However, the Lorentz contraction of the EM field has not been directly confirmed by an experiment. The first direct observation of the Lorentz contraction of the EM field was recently performed by using an electron linac at Osaka University (*). The electric field around an electron beam with an energy of 35 MeV and a pulse width of 0.72 ps was measured by an electro-optical (EO) sampling method. A 1mm-thick ZnTe crystal was used for EO sampling, and the polarization of optical laser light was modulated by the electric field around the electron beam in the crystal. The modulated laser light was decoded into a spatiotemporal image of the electric field and the Lorentz contraction was directly confirmed. The evolution of the newly generated electric field after passing the beam through a metallic boundary was also visualized. This ultrafast measurement technique can help longitudinal diagnostics of a charged particle beam.
High-resolution X-ray spectroscopy in the sub-nanosecond to femtosecond time range requires ultrashort X-ray pulses and a spectral X-ray flux considerably larger than that presently available. X-ray free-electron laser (XFEL) radiation from hard X-ray self-seeding (HXRSS) setups has been demonstrated in the past and offers the necessary peak flux properties. So far, these systems could not provide high repetition rates enabling a high average flux. We report the results for a cascaded HXRSS system installed at the European XFEL, currently the only operating high-repetition-rate hard X-ray XFEL facility worldwide. A high repetition rate, combined with HXRSS, allows the generation of millijoule-level pulses in the photon energy range of 6–14 keV with a bandwidth of around 1 eV (corresponding to about 1 mJ eV–1 peak spectral density) at the rate of ten trains per second, each train including hundreds of pulses arriving at a megahertz repetition rate. At 2.25 MHz repetition rate and photon energies in the 6–7 keV range, we observed and characterized the heat-load effects on the HXRSS crystals, substantially altering the spectra of subsequent X-ray pulses. We demonstrated that our cascaded self-seeding scheme reduces this detrimental effect to below the detection level. This opens up exciting new possibilities in a wide range of scientific fields employing ultrafast X-ray spectroscopy, scattering and imaging techniques.
LCLS-II first stage commissioning will be completed in the summer of 2023, with demonstration of 1kHz FELs using the superconducting CW electron beam. Operation-based electron beam and FEL commissioning will be continued with the goal of ramping up beam rate, improving the FEL performance, and developing advanced FEL operation modes. The commissioning challenges and the latest machine performance should be reviewed, and the next step plan for achieving the objective design performance should be discussed.
A new approach that demonstrates the guiding of relativistic electron beams over curved paths by means of a plasma-discharge capillary is presented. The magnetic field produced by the discharge current is used to deflect and focus the beam along a curved capillary, showing that the guiding can be made dispersion-less, i.e. not affected by chromatic dispersion. This proof-of-principle experiment extends the use of plasma-based devices that revolutionised the field of particle accelerators enabling the generation of GeV beams in few centimeters. Compared to state-of-the-art technology based on conventional bending magnets and quadrupole lenses, these results provide a compact and affordable solution for the development of next-generation table-top facilities.
Improving the performances of modern circular particle accelerators requires a tight and solid control of its linear optics. Decades of developments provided invaluable tools towards this end. This talk will review the historical milestones and the most recents novelties in this field.
Reinforcement learning (RL) is a unique learning paradigm inspired by basic principles of animal and human behavior, where the learning happens from the interaction with the environment. This interaction involves exploring and assessing the effectiveness of various strategies under different conditions. RL is particularly well-suited for addressing control problems in large environments, managing delayed consequences, and, through advanced techniques, learning from experiences without needing a model of the problem's dynamics. Such capabilities render RL methods highly promising for applications within particle accelerators, where the dynamic conditions of both the particle beam and accelerator systems necessitate continuous adaptation. Although the particle accelerator community has only recently begun to explore the potential of RL, yielding promising outcomes, the widespread application of these methods remains constrained. Challenges include formulating the control problem in a meaningful manner and deploying solutions in real-world systems. This presentation should provide an overview of RL applications in the context of particle accelerators, highlighting the current challenges the community faces and exploring promising directions for future research.
A program to develop K=500 superconducting cyclotron was launched in India at VECC, Kolkata during the beginning of this century. Such an accelerator was planned to be built to provide ion beams heavier compared to that provided by K=130 cyclotron in the same campus. Through this project, India ventured into the technology of superconducting cyclotron. Although the construction of this cyclotron was completed in the beginning of last decade and internal beam was observed, challenge was faced in getting the external beam. Massive R&D efforts were required to be initiated to overcome this challenge, and campaign was started to perform several magnetic field measurements at intricate locations, as a result of which it was understood that the problem was occurring due to field errors arising due to misalignment of superconducting coils. After making the required rectifications, first external beams (252 MeV N+4) were extracted in the beginning of this decade, and now efforts are ongoing to accelerate a wide variety of ion beam in this cyclotron. The proposed speaker will start by giving an introduction to the K=500 cyclotron project, briefly describing the milestones achieved in the project, and an account of the R&D efforts to diagnose the problems that were faced in extracting the beam, along with the beam commissioning results. Future plans for extending the operational regime further of the superconducting cyclotron will also be discussed by the proposed speaker.
Thursday Poster Session
Thursday Poster Session
Thursday Poster Session
Starting with my first experience of the transverse feedback damper in the KEK 12 GeV PS in 2006, where we tested with analog system and in addition digital controller from SPring-8 team. Since then, digital systems have come to cover almost all the machines. In J-PARC MR bunch-by-bunch transverse feedback system had been introduced with a collaboration at the proton beam power around 150 kW in 2010. The weaknesses of this system quickly became apparent. It can damp only the center of mass motions of the whole bunches. It could not suppress intra-bunch betatron motion with different betatron phase in a different longitudinal bunch position. This happens in the case of a non-zero chromaticity. Then the intra-bunch feedback system was introduced in 2014 with a proton beam power of approximately 250 kW and has been operating successfully to date. But already this system cannot suppress collective beam instabilities in certain chromaticities over proton beam intensity of 2 - 3E+14 protons per pulse. The higher the sampling rate, the higher the damping efficiency. This system is currently under development. The above is for long bunches of 100-200 ns. Trials in case of much shorter bunches will be also reviewed.
Review of Linear and Nonlinear Optics Measurements in the CERN LHC
The GSI facilities of CRYRING and HiTRAP are used for decelerating ion beams to low energies. This deceleration phase is preceded by the generation and acceleration of those ions. CRYRING and HiTRAP operate at the junction between accelerator science and atomic physics. The scientfic motivation, the operation principle, the state of the art and future outlooks are presented.
We will review interesting advances we have been able to perform in the domain of laser-driven generation of proton and neutron beams, using the new ultra-high power Apollon laser facility (France) [BUR]. Thanks to the ability to tailor the ultra-short timescales of the temporal pedestal of the laser pulse, we have notably been able to accelerate protons in a “lighthouse” fashion, whereby the highest-energy component of the beam is emitted in a narrow cone, well separated from the lower-energy components. As a result, the spectrum of the output protons can be easily adjusted by collecting them along a specific direction, therefore removing a major roadblock of these beams, which are otherwise spectrally broadband. This approach offers the advantages of leveraging a robust sheath acceleration process in standard micron-thick targets and being optically controllable. We have also demonstrated that, when enhancing the temporal contrast by using plasma mirrors, we could enhance the laser-to-target coupling and the proton energy, as well as reduce the angular divergence of the proton beams. Last, we will review the high flux neutrons that can be produced using these beams when using (p,n) reactions in Li [LEL]. The measured high fluxes that can be obtained using Apollon open perspectives for getting insight into nucleosynthesis of elements [HOR].
In this talk EIC construction status in BNL will presented, in which electron and protron accelerator complex will be shown in detail, including polarization scheme.
In this talk CEPC accelerator EDR satus will be presented, in which SRF system, magnets system, vacuum system, high power and high efficiency klystrons develpment, linac injector system, alignment and instatllation, MDI, civil engineering design and green collider technologies, etc will be covered.
The laser-based synchronisation systems for the European XFEL and FLASH provide femtosecond-stable timing references for tens of clients along the accelerator and the experiment halls over many kilometres of optical fibre. Recently, benchmarking experiments revealed a point-to-point timing stability with sub-femtosecond rms timing jitter. At the same time geophysical effects like ocean waves and earthquakes do not only affect the performance of the system, but their impact can clearly be identified. To improve the temporal resolution in X-ray/optical pump-probe experiments, additional arrival time monitors for both the electrons and the optical laser pulses are currently being installed, allowing for a posteriori data sorting and eventually active feedbacks. Further, the optical reference oscillators and advanced synchronisation schemes are being developed, resulting in timing jitter on the sub-hundred attoseconds level.
Summary: An experiment to fly an accelerator in space recently concluded successfully. Discuss the objectives, differences from terrestrial accelerators, and results from the flight.
Accelerators have the potential to play a major role in space-based activities. These can range from investigation of the Earth’s magnetic field, to helping mitigate the effects of increased solar activity (e.g. by helping drain the Earth’s radiation belts of charged particles), to deep-space missions. There are many challenges associated with operating accelerators in a space-based environment, however, ranging from high-voltage systems, to thermal management, to spacecraft charging. The Beam-Plasma Interaction Experiment – BeamPIE – was a small electron accelerator launched on a sounding rocket in 2023, to both explore the interaction of an electron beam with the near-earth plasma environment, and to test several new approaches to accelerator design in a space environment. This talk presents an overview of the BeamPIE accelerator design, mission objectives, and results from its flight.