bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimated heat load and proposed cooling system in the FCC-ee interaction region
Authors: Novokhatski A , Boscolo M , Fransesini F , Lauciani S , Pellegrino L 
Published: January 2024

Abstract
We discuss the beam power loss related to the heating of the beam pipe walls of the FCC-ee interaction region. We analyse the excitation of trapped modes, which can accumulate electromagnetic energy and determine the locations of these modes. We study the unavoidable resistive-wall wake field, which is responsible for the direct beam pipe walls heating. We show the distribution of the heat load along the central part of the interaction region. We also present the cooling system design and results for temperature distribution in interaction region in the operational mode.
Modification of Beam Transport Line Design for Simultaneous Top-up Injection to PF and PF-AR
Authors: Higashi N , Mitsuda C , Nagahashi S , Harada K , Nogami T , Uchiyama T , Nakamura N , Honda T , Satoh M , Okayasu Y , Enomoto Y 
Published: January 2024

Abstract
The High Energy Accelerator Research Organization (KEK) has two light sources: Photon Factory (PF, 2.5 GeV) and Photon Factory Advanced Ring (PF-AR, 6.5 GeV). In 2017, the operation of a new beam transport line (BT) of PF-AR was started, and the simultaneous top-up injection for both PF and PF-AR was realized. These days, there have been strong demands for the reduction of the operating cost of accelerators, and its importance is greater in PF-AR with higher ring-energy of 6.5 GeV. In 2019, the 5 GeV operation was started in PF-AR. However, the new BT of PF-AR (ARBT) was designed for the energy of 6.5 GeV, then the simultaneous top-up injection is no longer available under the condition of 5 GeV operation of PF-AR and 2.5 GeV operation of PF. In order to mitigate this impact, the pseudo-top-top injection has been employed by fine-tuning the current of a common DC bending magnet placed at the intersection of ARBT and the BT of PF (PFBT) within a given time frame. However, this scheme reduces the flexibility of the operation schedules, and will not be able to respond adequately to low emittance optics of PF-AR that may bring the shorter beam lifetime. In order to realize true-top-up injection, a modification of BTs’ optics design was carried out to add new horizontal steering magnets and a flattened-duct. The beam commissioning succeeded and the application to the user-run will start in this May. This time, details of modification and its extended plan will be presented.
Studies on a Triple-Turn Energy-Recovery Mode at the S-DALINAC
Authors: Schliessmann F , Arnold M , Brauch A , Dutine M , Fischer M , Grewe R , Juergensen L , Meier M , Pietralla N , Schneider D 
Published: January 2024

Abstract
The electron accelerator S-DALINAC at TU Darmstadt was successfully operated in single- and double-turn energy-recovery mode. The latter was realized using a shared beam-transport where two beams are superimposed in the first recirculation beamline. Due to its current design, the S-DALINAC can be upgraded with reasonable effort to be operated in triple-turn energy-recovery mode with shared beam-transport. Here, two beams are superimposed in both the first and the second recirculation beamline. This mode is particularly challenging since it does not allow for on-the-fly beam tuning compared to a triple-turn energy-recovery mode with individual beam-transport. Therefore, the triple-turn energy-recovery mode requires precise determination of the accelerator setup obtained from beam-dynamics simulations prior to beam-tuning. First results of the necessary beam-dynamics simulations for this mode are presented.
Fully coherent soft X-ray pulse generation based on ERL
Authors: Cao L , Cai M , Feng C , Wang Z , Chen S , Zhao Z T 
Published: January 2024

Abstract
Energy recovery linacs (ERLs) possess the bright prospect of fully coherent X-ray generation. Recently, we designed a 600 MeV energy recovery linac capable of producing high power fully coherent radiation pulses at 13.5 nm with a relatively low-intensity 256.5 nm seed laser profiting from the employment of angular-dispersion-induced microbunching (ADM) technology. We also designed a matched multiplexed system that can deflect each radiator by 8 mrad with a carefully choreographed multi-bend achromat (MBA) scheme. As a result of downstream MBA’s dispersion compensation, bunching factors will be enhanced both at the fundamental wavelength and high harmonics. The bunching factor of the 19th harmonic increased from 10% to 26%, and that of the 57th harmonic became 8.4%, which is sufficient to generate fully coherent radiation in the soft X-ray range.
Emittance Growth Study of an Electron Beam in a Double-Alpha Magnet Compressor Used in an Inverse Compton Scattering X-Ray Source
Authors: Pires A , Chauchat A , Collet M , Le Flanchec V , Delerue N 
Published: January 2024

Abstract
An Inverse Compton Scattering (ICS) X-ray source is under development at the ELSA (Electrons Laser X-Sources and Applications) electron RF linac of CEA DAM (Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Applications Militaires). X-rays are emitted by the interaction of 30 MeV electron bunches with Nd:YAG laser pulses. The electron bunches duration is 30 ps rms before compression in two alpha magnets. In such a system, electron trajectories are curved with a short radius, resulting in a noticeable degradation of the beam emittance. In the specific case of strongly curved trajectories, the straight trajectory and beam shape assumptions used for space charge calculation in most simulation codes are questionable. Two different approaches to the simulation of electron beam dynamics within the alpha magnets are compared. A specific method to deal with changes from the reference particle frame to the laboratory reference frame, which does not imply any trajectory and beam shape assumptions, is proposed. Calculation results are presented. Along with an important emittance growth, they show that more physical effects can be taken into account in the latter simulation.
Bending Magnet Photon Absorber Design and Calculations for the Elettra 2.0 Storage Ring
Authors: Scrimali G , Cudin I 
Published: January 2024

Abstract
To harness the major advances that have been done in the field of synchrotron light research, Elettra synchrotron radiation facility is being updated. Presently in its design phase, the Elettra 2.0 project will allow new and better research to be performed at the facility. In the upgrade of the storage ring, the new 6BA lattice brings challenges in terms of available space and radiated power. This paper presents the bending magnet photon absorber designed to cope with the new requirements. The absorber concept created for ESRF-EBS has been revised and re-engineered to make it suitable for the specific features of Elettra’s sources. To reduce the high-power densities induced by the short source-absorber distance, the one-jawed, toothed profile was obtained via a robust optimization, considering possible misalignments or beam miss-steering. Novelty of the approach is the absorber insertion in the vacuum chamber from the inside of the ring. Finally, presented are the thermo-mechanical and computational fluid dynamics simulations (ANSYS) performed to validate the design, comprehensive of a Monte-Carlo, ray-traced simulation to evaluate photon reflections (SYNRAD) and their effects.
Photoelectron spectroscopy of CsK2Sb photocathode at Synchrotron Radiation Facility using vacuum transport system
Authors: Shiohara K. , Guo L. , Yamaguchi H. , Takashima Y. 
Published: January 2024

Abstract
As accelerators and electron microscopes become more advanced, high-performance photocathodes are required. In particular, Cesium potassium antimonide (CsK2Sb) photocathode is of interest because of its low emittance, excitability in visible light, and high quantum efficiency (QE). The challenge is its high susceptibility to environment that lead to low operating vacuum pressure and short lifetime/low extraction charge. To resolve these issues, it is necessary to understand the molecular structure of the cathode and its degradation mechanism. In this study, we transported CsK2Sb photocathode to a beamline of synchrotron radiation facility using a vacuum transport system for molecular structure analysis. Specifically, the cathode was deposited in an evaporation system at Nagoya University. We transported it to Aichi Synchrotron Radiation Center (Aichi SR) located 15 km away, and analyzed it in the depth direction by X-ray photoelectron spectroscopy (XPS) at BL7U. Based on the results, we quantitatively evaluated the composition ratios and stoichiometry of the cathode elements (Sb, K, Cs). A Cs ex-cess state of surface was observed at the surface, and it is consistent with previous studies. The intended atomic structure of CsK2Sb was formed only at a few nanometres of the surface on the Mo substrate. On the other hand, the CsK2Sb cathode structure on the graphene substrate was preserved further in the depth direction.
Test of a DC-photogun injector for the Lighthouse facility
Authors: Blokesch G , Grewe M , Keune B , Krämer J M , Kümper V , Piel C , Quitmann C , Trinh T , Hoffstaetter G 
Published: January 2024

Abstract
Worldwide there is a push for producing medical isotopes using particle accelerators rather than fission reactors. Here we report on the operation of the beam test facility (BTF), set up and operated at the RI site in Bergisch Gladbach, Germany, comprising a dc-photogun designed for producing 99Mo in the Lighthouse facility and commissioned by the Institute for Radio Elements (IRE, Belgium) [1]. The gun is based on the successful CBETA design by the Cornell University[3]. The existing design has been reworked and integrated with a fully automatable photocathode production facility (PPF) designed for series production and exchange of photocathodes (PC).
Dynamics of off-axis injection near the coupling resonance at PETRA IV
Authors: Cortés García E.C. , Agapov I.V. 
Published: January 2024

Abstract
The PETRA IV project will have a storage ring with an ultra-low natural emittance of 20 pm rad. For an off-axis injection scheme with working points at the difference resonance, it is critical to ensure that the vertical excursion caused by transversal coupling does not affect injection efficiency. In this contribution, we present simulation results of an off-axis injection near the coupling resonance, which provides equal equilibrium emittances. The advantages and disadvantages of such a scheme are discussed.
Calibration of the 2-Phase Bubble Tracking Model for Liquid Mercury Target Simulation with Machine Learning Surrogate Models
Authors: Lin L , Tran H , Radaideh M , Hoover A , Winder D , Cousineau S 
Published: January 2024

Abstract
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is one of the most powerful accelerator-driven neutron sources in the world. The intense protons strike on SNS’s mercury target to provide bright neutron beams, which also leads to severe fluid-structure interactions inside the target. Prediction of resultant loading on the target is difficult particularly when helium gas is injected into mercury to reduce the loading and mitigate the pitting damage on vessel walls. A 2-phase material model that incorporates the Rayleigh-Plesset (R-P) model is expected to address this multi-physics problem. However, several uncertain parameters in the R-P model require intensive simulations to determine their optimal values. With the help of machine learning and the measured target strain, we have studied the major uncertain parameters in this R-P model and developed a framework to identify optimal parameters that significantly reduce the discrepancy between simulations and experimental strains. The preliminary results show the possibility of using this mercury/helium mixture and surrogate models to predict a better match of target strain response when the helium gas is injected.
AISHa: an ECRIS for nuclear-physics, new clinical protocols and material experiments
Authors: Celona L. , Leonardi O. , Castro G. , Gammino S. , Neri L. , Costanzo G. , Chines F. , Siliato D. , Passerello S. , Russo F. , Calabrese G. , Marletta S. , Vercesi V. , Lanza A. , Kourkoumeli A , Ramos R. L. , Scagliotti C. , Vercellati F. , Falbo L. , Maugeri C. , Monferrato R. , Sironi S. , Vigon A. 
Published: January 2024

Abstract
The Advanced Ion Source for Hadrontherapy (AISHa) is an ECR ion source operating at 18 GHz, developed with the aim to produce multiply charged ion beams with low ripple, high stability and reproducibility. Due to its unique peculiarity, it is the most suitable choice for medical applications, but also for nuclear-physics and material experiments. Two sources have been realized: the first at INFN-LNS and the second at the Centro Nazionale di Adroterapia Oncologica (CNAO). The first one, fully commissioned at INFN-LNS, will be used as test-bench for development of new beams and several R&D activities are planned within the IONS experiment to increase plasma confinement and to refine techniques of non-invasive plasma diagnostics to correlate plasma and beam parameters. The second one recently produced the first beam and it will allow to increase the CNAO potential in the field of experimental and industrial research, with the long-term goal of introducing new ionic species into clinical practice such as helium, oxygen and later also iron and lithium, useful for bio-spatial research. In this work, the key peculiarities and the experimental results of the two Aisha ion sources will be presented.
Beam Dynamics Studies for the Target Beamlines of the High Brilliance Neutron Source
Authors: Lehrach Andreas , Baggemann Johannes , Felden Olaf , Gebel Ralf , Gutberlet Thomas , Podlech Holger , Zakalek Paul 
Published: January 2024

Abstract
The High Brilliance Neutron Source (HBS) belongs to the class of High Current Accelerator based Neutron Sources (Hi-CANS). The driver Linac for the HBS must be able to reliably accelerate a 100 mA proton beam to an energy of 70 MeV [2, 1, 3]. The beam is sent pulse-by-pulse to three different targets via a multiplexer in the High Energy Beam Transfer (HEBT) section. Each individual proton pulse behind the multiplexer has a specific time structure in order to optimally serve the different instruments grouped around one target station. The main development steps of the HEBT are the development of a three-field septum magnet, which is an essential part of the multiplexer magnet system, the beam dynamics integration of the multiplexer magnet system into the beamline, and the ion-optical layout of the individual target beamlines.
Simulation and measurement of beam loading effects in magnetic alloy rf cavity of CSNS RCS
Authors: Liu Hanyang , Huang Liangsheng , Liu Yang , Xu Shouyan , Wang Sheng 
Published: January 2024

Abstract
Different from the ferrite cavity, the Q value of magnetic alloy cavity in CSNS RCS is only about 1.25, the frequency band of impedance is wide, and the beam loading effects is strong. Based on the impedance measurement results, the influence of the beam loading effects on the longitudinal distribution of the magnetic alloy cavity in CSNS RCS is studied by simulation, and the induced voltage measured on the machine is consistent with it.
Fabrication progress of the prototype spoke cavity for the JAEA-ADS linac
Authors: Tamura J , Kondo Y , Yee-Rendon B , Meigo S , Maekawa F , Kako E , Umemori K , Sakai H , Dohmae T 
Published: January 2024

Abstract
The Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven nuclear transmutation system (ADS) as a future nuclear system. In preparation for the actual design of the CW proton linac for the JAEA-ADS, we are now prototyping a low-β (≈ 0.2) single-spoke cavity. The cavity fabrication started in 2020. Most of the cavity parts were shaped in fiscal year 2020 by press-forming and machining. In 2021, we started welding the shaped cavity parts together. By preliminarily investigating the optimum welding conditions using mock-up test pieces, each cavity part was joined together with smooth welding beads. So far, we have fabricated the body section and the beam port sections. By measuring the resonant frequency of the temporarily assembled cavity, it was confirmed that there were no significant problems with the cavity fabrication.
Accelerator and beam physics challenges in support of FRIB experiments
Authors: Ostroumov P N , Fukushima K , Hwang K , Maruta T , Plastun A , Wei J , Zhang T , Zhao Q 
Published: January 2024

Abstract
The Facility for Rare Isotope Beams (FRIB), a major nuclear physics facility for research with fast, stopped and reaccelerated rare isotope beams, started operation in May 2022. Since then, a dozen nuclear physics experiments have been successfully accomplished. Typically, the experiments with rare isotope beams last a week or two. Each experiment requires a different primary beam species and energies. Shortening the accelerator and fragment separator setup time is critical to meet the demands of the FRIB Users community. Currently, the primary focus in the linac is reducing the accelerator setup time and beam power ramp-up. Many physics applications have been developed and used to set up the accelerator and beamlines. The simultaneous acceleration of multiple charge states of heavy ion beams is routinely used to minimize the beam power deposition on the charge selector slits after the stripper. This paper discusses the challenges of linac tune development for the acceleration of various ion species.
Future ESS upgrade to Medium Pulse Length – What are the technical challenges for the accelerator and target?
Authors: Lindroos M. , Arai M. , Danared H. , Deen P. , Eshraqi M. , Jones B. , Milas N. , Miyamoto R. , Odén U. , Plostinar C. , Santoro V. , Schweika W. , Zanini L. , Carlile C. , Ekelöf T. , Olvegård M. , Machida S. , Prior C. 
Published: January 2024

Abstract
A compression of the ESS proton pulse from the present 2.86 milliseconds to a medium pulse length of a few tens of microseconds which is better matched to the moderator time-constant of thermal neutrons would considerably boost the performance for many instruments at ESS. Generating such a proton pulse with preserved instantaneous beam power requires a storage ring to be added to the ESS accelerator. Such a ring has been studied within the ESSnuSB neutrino super-beam study. The proton pulse length extracted in single turn extraction from this ring would be approximately 1 microsecond long which could be destructive for the present ESS target and is very short compared to the moderator time constant. The more desirable medium length pulse could possibly be generated by multi-turn extraction and a new concept using a cyclotron like extraction scheme in a synchrotron or a FFA. Another way to generate the longer pulses is to extract a bunch train using fast strip line kickers but this would require a larger storage ring. Using a “bunch train” has been successfully applied at the CERN ISOLDE facility to avoid destruction of sensitive liquid metal targets used for Nuclear Physics experiments. Other challenges are linked to the injection into the storage rings and the understanding of the target, moderator and neutron extraction systems with short and medium pulse length.
Operational tests of CRYRING@ESR without electron cooler solenoid compensation
Authors: Krantz C , Andelkovic Z , Dimopoulou C , Fedotova S , Geithner W , Herfurth F , Heß R , Kraus I , Khammee S , Lestinsky M , Reiter A , Roβbach J , Trotsenko S , Vorobyev G 
Published: January 2024

Abstract
We have tested operation of FAIR’s low-energy ion storage ring CRYRING@ESR with uncompensated electron cooler solenoid. With its standard working point on the lowest-order difference resonance, a second solenoid is normally used to cancel betatron coupling introduced by the cooler’s magnetic field. In operation with a D+ test beam, we found that omission of the compensation solenoid did not lead to a notable deterioration of beam intensity, quality, or cooling time, though the expected coupling of betatron motion is then clearly observed.
Tailoring transverse beam characteristics with the new CERN PS Booster charge-exchange injection system
Authors: Renner E , Albright S , Antoniou F , Asvesta F , Bartosik H , Bracco C , Di Giovanni G P , Mikulec B , Prebibaj T , Skowronski P , Velotti F M 
Published: January 2024

Abstract
A key aspect of the LHC Injectors Upgrade project is the connection of the PSB to the newly built Linac4 and the related installation of a new 160 MeV charge-exchange injection system. The new injection system was commissioned in winter 2020/21 and is now used operationally to tailor the transverse characteristics for the various beam types at CERN, such as high-intensity fixed target beams, LHC single bunch beams, and high-brightness beams for LHC. This contribution outlines the different injection strategies for producing the various beam types and discusses the application of numerical optimization algorithms to adjust injection settings in operation efficiently.
Optimization of low-energy slow extraction efficiency of XiPAF
Authors: Wang Z J , Yao H J , Yang Y , Liu X Y , Li Y , Xiong Y , Zheng S X , Wang X W 
Published: January 2024

Abstract
Xi’an Proton Application Facility (XiPAF) synchrotron provides 10∼200MeV proton beam for the experimental simulation of the space radiation environment. Due to the space charge effect, the slow extraction of 10 MeV proton beam is a work full of challenges. In a past experiment, the total extraction efficiency was over 65% with 4.5 ∽ 6.5×1010 protons stored before extraction but decreased to 52% with 9×1010 protons stored. In order to study the beam loss caused by a strong space charge effect, based on experimental parameters, the beam loss fractions at different positions of XiPAF synchrotron are obtained through the simulation. According to the beam loss analysis, optimized parameters are found for reference in subsequent experiments. It is also noted that negative beam average momentum spread before extraction is beneficial to the improvement of extraction efficiency.
OffSet measurements at Rapid Cycling Synchrotron in China Spallation Neutron Source
Authors: An Yuwen , Li Yong , Lu Xiaohan , Xu Shouyan 
Published: January 2024

Abstract
The Rapid Cycling Synchrotron(RCS) is the key part of the China Spallation Neutron Source(CSNS) with a repetition rate of 25 Hz. The lattice of the RCS is based on triplet cells with a superperiod of four. Due to the utilization of the trim quadrupoles in June 2021, the Beam Position Monitor(BPM) offsets have been carefully measured, and the beam operation is more stable. In this paper, we will review the preparation of BPM offsets measurements with the virtual accelerator and the experimental results in beam commissioning.
Design of the gradient dipole magnet for LLICTF
Authors: Chu Yimeng , Wang Zhijun , Huang Junren , Chen Weilong , Xu Zhenyu , Liang Zehua , Sun Kunxiang 
Published: January 2024

Abstract
The Lanzhou Light Ion Cancer Therapy Facility (LLICTF) is a compact medical accelerator currently under construction. It is designed to treat cancer using a 230 MeV, 30 mA H+ beam and a 85 MeV/u, 1 mA 3He2+ beam. The facility comprises two ion sources, a low-energy beam-transport (LEBT), a Radio Frequency Quadrupole (RFQ), a medium-energy beam-transport (MEBT), and the main ring accelerating structure. Due to the presence of two ion sources, it is necessary to introduce a dipole magnet which is symmetrically focused as much as possible to meet the focusing requirements of the LEBT beam. Therefore, a gradient dipole magnet has been designed to achieve this symmetrical focusing. This paper discusses the theoretical and simulated symmetric focusing of the gradient dipole magnet. It also analyzes the effect of fringe fields and space charge. Additionally, this paper presents the results of the model design with CST and the multi-particle simulation results with TraceWin.