bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benchmarking the FCC-ee positron source simulation tools using the SuperKEKB results
Authors: Alharthi F. , Chaikovska I. , Chehab R. , Zhao Y. , Latina A. , Enomoto Y. , Miyahara F. , Mytrochenko V. 
Published: January 2024

Abstract
For the Future Circular Collider (FCC-ee), particular attention is drawn to the crucial role of the positron source. Two positron production schemes are considered for the FCC-ee: the conventional scheme and the crystal-based (hybrid) scheme that involves channelling radiation in the oriented crystals. A start-to-end simulation toolkit should be developed to design and optimize positron production and capture by considering the positron injector parameters, including the electron drive beam and final system acceptance. This paper presents the first results of benchmarking the FCC-ee positron source simulation tools using the SuperKEKB positron source currently in operation. The model starts with the production of positrons and target studies in Geant4. Then, the RF-Track code is used to capture and track the generated positrons through the capture section composed of a matching device and several accelerating structures embedded in the solenoid field to accelerate the positrons up to 120 MeV. After that, the positrons are further accelerated up to the energy of the Damping Ring (1.1 GeV). Finally, the SuperKEKB capture system is applied to the FCC-ee positron injector within the framework of the design studies.
Beam Loading Compensation of Traveling Wave Linac to a Multi-bunch Pulse with Gaps
Authors: Kuriki M , Kuroguchi S , Tajino H , Takahashi T , Liptak Z , Omori T , Urakawa J , Yokoya K. 
Published: January 2024

Abstract
In the electron driven ILC (International Linear Collider) positron source, the beam is generated and accelerated in a multi-bunch format with mini-trains. The macro-pulse contains 2 to 4 mini-trains with several gaps, because the pulse format is a copy of a part of the bunch storage pattern in DR (Damping Ring). This pulse format causes a variation of the accelerator field in the pulse due to the transient beam loading and an intensity fluctuation of captured positron. The beam loading is compensated by amplitude modulation on the input RF in the positron booster composed from L-band and S-band traveling wave RF cavity. In this article, we derive the exact solution for the compensation with the gaps. In addition, we evaluate the effect of the time constant (delay) of the input RF modulation due to klystron Q-value.
Design, testing, and validating the CLIC module pre-alignment and alignment systems
Authors: Capstick M , Doebert S , Rossi C , Brown J 
Published: January 2024

Abstract
The Compact Linear Collider requires micron-level alignment of the key accelerator components within the two 21 km main LINACs to achieve the desired luminosity. Several Super Accelerating Structures (SAS) will be pre-aligned on a single common support structure to within 14μm. This common support structure will then be actively aligned relative to a Machine Reference Network, and in operation beam-based alignment will be used to achieve the final 1 μm alignment required. A design for the SAS pre-alignment system has been created, prototyped, and tested, and shown to match the design performance within 2.3 μm/turn, and to meet the specification requirements. A design for the active girder alignment system has also been created, prototyped, and initial testing has begun. This testing indicates that the system works as designed. Finally, the testing required to confirm this, and to fully validate the CLIC alignment procedure, is discussed.
An iterative algorithm to estimate the energy spectrum of an electron beam from PDD curves
Authors: Nichelatti Enrico , Astorino Maria Denise , Borgognoni Fabio , Ronsivalle Concetta 
Published: January 2024

Abstract
Electron beam central-axis percentage depth dose (PDD) curves in water phantom are routinely employed to evaluate the electron beam energy at the phantom surface, in particular the mean and most probable energies from the values of R
50 (half-value range) and Rp
(practical range). However, these two quantities are not enough to evaluate important details of the energy distribution, such as the FWHM (Full Width Half Maximum) and the possible presence of a low-energy tail. This paper presents a numerical method that allows estimating the shape of the energy spectrum from a PDD curve. The algorithm uses a database consisting of a set of depth dose curves for monochromatic beams computed by FLUKA in the range 0.1-7.0 MeV by steps of 0.1 MeV and, using an adaptive iterative Monte Carlo process, reconstructs the incident energy spectrum by minimizing the distance between the measured PDD and the computed one. Applications of a MATLAB code based on this algorithm to simulated and real measurements of electron beams done at APAM lab (ENEA Frascati) are presented. This approach represents a strong simplification with respect to energy analysis based on the use of a magnetic spectrometer.
Design Modelling of RF Injector for ICS Gamma-Ray Source System
Authors: Tracz P , Iuciuc E 
Published: January 2024

Abstract
High brightness beams are desired for application to Inverse Compton Scattering (ICS) systems for generation of high-quality x- and γ-rays. In the ICS mechanism high energy electron is interacting with photon. It results in scattered photon with high energy. Computer simulations of electron beam in the rf injector for ICS γ-rays source were carried out and results are presented. Different configurations of injector model were analysed.
Radio Frequency System, Power Converters and Cryomodule installation and tests as a Polish in-kind contribution to the European Spallation Source (ESS)
Authors: Bocian D , Gaj W , Halczynski P , Krawczyk A , Lipka A , Ryncarz T , Skalka F , Sienkwicz M , Skiba M , Swierblewski J , Wartak M , Zwozniak A 
Published: January 2024

Abstract
The European Spallation Source (ESS) project currently enters the final stage of installation. Since 2017, a group of engineers and technicians from The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Science (IFJ PAN) are involved in the project. The contribution to the project can be divided into three main tasks: Radio Frequency Distribution System (RFDS), RF (Radio Frequency) Power Stations and Cryomodules.
The RFDS in ESS project is one of the largest installations of this type consisting of 155 RF high power systems. Engineers and technicians from IFJ PAN were responsible for preparation, installation and RF measurements of the above-mentioned system. The team is also involved in preparation and conducting low and high power tests of the RF stations.
The IFJ PAN team is also responsible for the preparation as well as vacuum and cryogenic tests for 9 Medium and 21 High Beta Cryomodules, before they are installed in the tunnel.
The advanced quality control and quality assurance were mandatory for this work because the costs of failures, as well as potential delays, would have a huge impact in the project realisation. Therefore dedicated methods and approaches have been adapted to this work using experience gained by the IFJ PAN team on previous projects like LHC, XFEL and W7X.
Slow Extraction Techniques from Fixed Field Accelerators
Authors: Taylor R , Steinberg A. F. , Pasternak J , Appleby R. B. , Sheehy S. L. , Benedetto E 
Published: January 2024

Abstract
Fixed Field Accelerators are a candidate for future hadron cancer therapy facilities as their high repetition rate and large energy acceptance enables novel treatment modalities such as high dose rate FLASH. However, conventional dose delivery mechanisms are still necessary, requiring continuous beam delivery over 1–30s. This work is the first study of slow extraction from a scaling Fixed Field Accelerator, using the LhARA facility for baseline parameters. At a horizontal tune of 10/3, the intrinsic sextupole strength of the nonlinear FFA magnetic field is sufficient to excite the resonance, although extraction is better controlled using an additional excitation sextupole at a tune close to 8/3, with radiofrequency knock-out extraction. Including considerations of issues due to nonlinear fields and limitations required to keep the tune energy-independent, slow extraction from Fixed Field Accelerators is successfully demonstrated.
Numerical analysis on the air conditioning system of the experimental hall at TPS
Authors: Chang J C , Chan W S 
Published: January 2024

Abstract
Taiwan Photon Source (TPS) had delivered the first synchrotron light on the last day of 2014. Installation of 16 beamlines of the first and second phases of TPS beamline project was completed. The third phase project also was launched in 2021. To confront the situation that the experimental hall is more compact, we performed Computational Fluid Dynamic (CFD) simulation to analyse the effects of the air conditioning system and various heat sources to the temperature and flow fields in the experimental hall.
A pulser R&D for the HEPS booster bumper magnet
Authors: Wang Guanwen , Chen JinHui , Huo Lihua , Liu Peng , Wang Lei , Shi Xiaolei , Duan Zhe , Shi Hua , Wu Guanjian , Zhai Xinzhe 
Published: January 2024

Abstract
The High Energy Photon Source (HEPS) is a fourth generation photon source, including a storage ring, a booster ring and a Linac. Due to the small dynamic aperture of the storage ring, a novel on-axis swap-out injection scheme was chosen. Here, the 6GeV booster acts as an accumulating ring during that injection process. To extract 6 GeV beam from the booster before injection into the storage ring, four slow bumper magnets are applied to assist the extraction kicker to accomplish. The bumper pulse magnetic field waveform is a half-sine wave with 1ms pulse bottom width. Depending on the simulation and test, a classic LC resonance circuit topology with IGBT switching in series with fast recovery diodes is adopted. In addition, an energy recycle circuit and capacitor charging circuit are designed, to decrease power loss and reduce the influence on the output pulse current waveform during the capacitor re-charge process. A pulsed power supply prototype has been completed, and the testing results show that the bumper pulser can fully meet the all requirements of HEPS booster high energy extraction system.
ByPass optics design in NICA storage ring for experiment with polarized beams for EDM search
Authors: Kolokolchikov S , Aksentyev A , Melnikov A , Senichev Y , Syresin E , Ladygin V 
Published: January 2024

Abstract
Experiments with polarized beams for EDM search in the NICA accelerator complex implies the design of an additional ByPass channels. Such alternative channels will make possible to use NICA as a storage ring and get enough statistical data.
Spin coherence and betatron chromaticity of deuteron beam in NICA storage ring
Authors: Kolokolchikov S , Aksentyev A , Melnikov A , Senichev Y 
Published: January 2024

Abstract
A distinctive feature of the ”Quasi-Frozen Spin” mode in the synchrotron is the installation of special elements with both electrical and magnetic fields on straight sections that compensate spin rotation from MDM on arcs. Moreover, due to the presence of the longitudinal emittance and the momentum spread inside the beam, spin rotation may occur incoherently. In order to suppress this effect, sextupoles are installed, which also affect the suppression of chromaticity.
A Novel Dual-Channel Kicker for the Hefei Advanced Light Facility
Authors: Shang F. L. , Song W. , Shang L. 
Published: January 2024

Abstract
Hefei Advanced Light Facility (HALF) is designed as a fourth-generation light source based on the diffraction-limited storage ring (DLSR). The pre-research for this design is complete. Due to the smaller beam dynamic aperture, about 6 mm, a novel dual-channel kicker has been purposed and designed, with other two traditional kicker, combined the new injection system bump system. This paper presented the principle and layout and the detail of the novel dual-channel kicker.
Precise control of a strong X-Y coupling beam transportation for J-PARC muon g-2/EDM experiment
Authors: Iinuma Hiromi , Abe Mitsushi , Sasaki Ken’ichi , Nakayama Hisayoshi , Mibe Tsutomu , Ogawa Shinji , Yamanaka Takashi , Sato Yutaro 
Published: January 2024

Abstract
A strategy for designing a dedicated beam injection and storage scheme for the J-PARC Muon g-2/EDM experiment is described. To accomplish a three-dimensional beam injection into the MRI-type compact storage system, transverse beam phase spaces (X-Y coupling) and a pulsed kicker system are key to controlling the vertical motion inside the storage volume. Moreover, dedicated beam phase control through the beam channel of the storage magnet’s yoke is crucial. We introduce a five-dimensional phase-space correlation in addition to strong X-Y coupling to control the stored vertical beam size to a level as small as one-third that achievable by X-Y coupling alone.
Demonstration of Three-dimensional Spiral Injection for the J-PARC Muon g – 2/EDM Experiment
Authors: Matsushita R. , Iinuma H. , Oda K. , Ohsawa S. , Nakayama H. , Rehman M. A. , Furukawa K. , Saito N. , Mibe T. , Ogawa S. 
Published: January 2024

Abstract
In the J-PARC Muon g-2/EDM experiment, to measure muon anomalous magnetic moment (g-2) and electrical dipole moment (EDM), it is necessary to accumulate 300MeV/c muon beams with a 66 cm diameter region with a 3 T solenoid-type magnetic field. A new three-dimensional spiral injection scheme has been invented to achieve this target. Since this is the first instance to employ this injection scheme, a scale-down experiment with an electron beam of 297 keV/c and storage beam diameter of 24 cm is established at KEK. A simplified storage beam monitor using scintillating fiber has been designed and fabricated to measure the stored beam. The 100 ns width pulsed beam is injected and the signal maintains a few microseconds by the stored beam observed. According to this result, the beam storage is confirmed. The recent result implies that the stored beam deviated from the design orbit and caused betatron oscillations. To measure the beam deviation quantitatively and tune the beam, the storage monitor has been updated. The data from this stored beam monitor are the primary data for considering the conceptual design of the beam monitor for the muon g-2/EDM experiment. This poster will discuss the measurement of beam storage by three-dimensional spiral injection and beam tuning using a scintillating fiber monitor.
Field Quality Improvement of Septum Magnets for SuperKEKB Injection System
Authors: Mori T , Kikuchi M , Kodama K , Mimashi T , Naito T , Sakamoto Y , Takasaki S , Tawada M , Ueda T 
Published: January 2024

Abstract
The SuperKEKB accelerator is a electron-positron collider consisting of the 7 GeV electron ring (high energy ring or HER) and the 4 GeV positron ring (low energy ring or LER). The commissioning of the SuperKEKB accelerator is underway, aiming to supply a great number of interaction events of electrons and positrons to the Belle II detector which is used for discovering the new physics beyond the standard model. The important milestone is to obtain integrated luminosity of 15 ab–1 in the next decade, so that the luminosity should exceed 2 × 1035 cm–2s–1 in several years. To achieve the goal, both rings have to be filled with high current beam of a few amperes, where the high injection efficiency is vitally important because lifetime is expected to be very short. One of the key components of the injection system is the septum magnet. It has been found that a transverse fringe field near the septum plate has sizable multipole components. A tracking simulation shows such fringe fields generate a vertical non-Gaussian tail, which could cause a beam background as well as a bad injection efficiency. Though quadrupole component in the multipoles could be, in principle, cancelled by adjusting the quadrupole magnets in the upstream of the beam line, it turned out to be difficult in actual operation. Even the quadrupole component was perfectly cancelled, components higher than quadrupole would be still harmful, since it generates a beam halo in the ring after injection, which increases the beam backgrounds to the Belle II detector. This paper describes about improvement of the field quality of the septum magnet.
Commissioning simulations tools based on python Accelerator Toolbox
Authors: Liuzzo S. M. , Carmignani N. , Carver L.R. , Hoummi L. , Perron T. , White S. , Agapov I. , Boese M. , Hellert T. , Keil J. , Malina L. , Musa E. , Veglia B. 
Published: January 2024

Abstract
Storage ring commissioning-like simulations are necessary to assess the feasibility of proposed future lattice designs. This paper proposes a python package for commissioning-like simulations based on python accelerator toolbox (pyAT). The software includes: 1) errors definition, 2) correction routines from open trajectory to optics and coupling correction and 3) the evaluation of the relevant parameters, such as dynamic aperture (DA), injection efficiency (IE) and Touschek lifetime (TL). The software is fully exploiting parallel resources (local or on a computing cluster) and is thought to be easily configured for any machine (examples are given for EBS DBA and HMBA, for PETRA IV and for FCC-ee). Whenever possible analytic formulas are made available to the user. Several examples are detailed in this paper and included in the code as demonstrations of use.
Development of fast BBA for Diamond Light Source
Authors: Appleby J M , Abbott M G , Fielder R T , Gaughran M J 
Published: January 2024

Abstract
Beam-based alignment (BBA) is a standard tool at accelerators for aligning particle beams to the centre of quadrupole magnets. Traditional BBA measurements have been slow, potentially taking many hours for a whole machine. We have developed a tool, based on results previously reported at the ALBA synchrotron, that uses fast excitation of magnets to speed up measurements. We show the results of different measurement and analysis techniques in comparison to the currently used slow method.
Light Source Developments at UVSOR BL1U
Authors: Katoh M. , Ota H. , Yamazaki J. , Hayashi K. , Okano Y. , Salehi E. , Taira Y. , Mano A. , Fujimoto M. , Takashima Y. , Hosaka M. , Sakamoto F. , Kaneyasu T. , Zen H. 
Published: January 2024

Abstract
UVSOR, a low energy synchrotron light source, has been operational for about 40 years. It has been providing high brightness VUV radiation to users but also providing a research environment for light source developments. BL1U is a dedicated beamline for developments and applications of novel light source technologies. The beamline is equipped with two variable-polarization undulators with a phase-shifter magnet and with a femto-second laser system which is synchronized with the RF acceleration. We have been studying oscillator-type free electron laser, coherent harmonic generation, coherent synchrotron radiation, inverse Compton scattering and spatiotemporal-structured light. We have also been exploring their applications, in collaboration with researchers from universities and research institutes.
Photocathodes for the electron sources at FLASH and European XFEL
Authors: Juarez-Lopez D.P. , Lederer S. , Schreiber S. , Brinker F. , Monaco L. , Sertore D. 
Published: January 2024

Abstract
FLASH at DESY (Hamburg, Germany) and the European XFEL photoinjectors are operated by laser driven RF-guns. For both user-facilities cesium telluride (Cs2Te) photocathodes are successfully used since several years. We present recent data on the lifetime and quantum efficiency (QE) of the current photocathode at FLASH #105.2, operated before and after a long shutdown. In addition, data for the cathodes that recently have been exchanged at the European XFEL will be presented.
Recent progress of THz source at the SXFEL
Authors: Kang Y , Sun H , Zhang K Q , Feng C 
Published: January 2024

Abstract
Coherent, wide-tunable frequency and high intensity terahertz (THz) source is under preparation at the Shanghai Soft X-ray free-electron laser facility (SXFEL). The electron bunches modulated by frequency beating light can generate coherent, wide-tunable, high intensity THz radiation from 0.1 to 30 THz through wigglers. The electromagnetic wiggler with peak magnetic field up to 1.75 T is adopted and the parameters of the wiggler are optimized to ensure the generation of strong field THz radiation. Due to the limitation of layout space of the SXFEL, the length of wiggler is limited within 5 meters. By properly increasing the charge of the electron beam, the THz pulse energy can be kept at sub mJ level under the proposed different parameters of the wiggler. In this article, we will present the possible layout of THz source on the SXFEL and the S2E simulation of THz radiation of sub mJ magnitude within the 5-meter wiggler.
High-gain free-electron laser with orbital angular momentum seeded by an x-ray regenerative amplifier
Authors: Sun Hao , Feng Chao , Liu Bo 
Published: January 2024

Abstract
High-gain high-mode generation (HGHMG) free-electron laser has been experimentally confirmed to produce vortex light from a relativistic electron beam and is proposed to generate fully-coherent, high-brightness hard x-ray carrying orbital angular momentum at modern free electron laser facilities. However, this requires a coherent x-ray seed laser with sufficient power to perform the helical modulation on the electron beam. In this contribution, we propose a promising scheme to generate a fully coherent x-ray seed laser for the HGHMG system. In this scheme, an x-ray regenerative amplifier is used to offer a fully coherent x-ray seed laser to modulate the electron beam in a helical undulator. With the proposed technique, high-power and high-repetition-rate x-ray with orbital angular momentum can be produced, which will open routes to scientific research in x-ray science.
Carrier-envelope phase stabilization in FEL oscillators
Authors: Hajima R , Kawase K , Zen H , Ohgaki H 
Published: January 2024

Abstract
FEL oscillators can produce few-cycle optical pulses with a high-extraction efficiency when the oscillators are operated in the superradiant regime. Such FEL oscillators are unique light sources to explore intense light field science, especially in mid-infrared and longwave infrared where ultrashort pulses for the high-intensity applications are difficult to produce from conventional lasers. Since the laser-matter interaction in the intense field regime is described in terms of the oscillating electric field rather than the instantaneous intensity, the carrier-envelope phase (CEP) must be stabilized in many applications of few-cycle optical pulses to the intense light field science. Stabilization of CEP in FEL oscillators has been proposed with an external seed laser and coherent spontaneous emission from the electron bunches. In this paper, we study CEP stabilization in FEL oscillators assisted by coherent spontaneous emission from electron bunches with numerical simulations.