bluuebunny/crossref_metadata_2025_split huggingface dataset:
Beam dynamics optimization of EuPRAXIA@SPARC_LAB RF injector
Authors: Silvi G J , Bacci A L , Carillo M , Chiadroni E , Faillace L , Francescone D , Giribono A , Iovine P , Mostacci A , Ferrario M , Pompili R , Vaccarezza C 
Published: January 2024

Abstract
At EuPRAXIA@SPARC_LAB an X-ray FEL user facility is driven by a plasma accelerator in the particle-driven configuration where an ultra-relativistic beam, the driver, through a plasma generates a wake of charge density useful for accelerating a witness beam. The electron bunches are generated through the so-called comb technique in an RF injector that consists of a 1.6-cell S-band gun followed by four S-band TW accelerating structures. The main working point foresees a 30pC witness and a 200pC driver longitudinally compressed in the first accelerating structure operated in the velocity-bunching regime, which allows to accelerate and manipulate the beam to reach proper transverse and longitudinal parameters. The optimization of the witness emittance is performed with additional magnetic field around the gun and the velocity bunching S-band structures and by shaping the laser pulse at the cathode. The paper reports on beam dynamics studies performed also with the insertion of an X-band RF cavity after the gun that is proposed to shape the beam current distribution and stabilize it with respect to RF jitters.
Electron cloud build-up studies for FCC-ee
Authors: Sabato L , Pieloni T , Iadarola G , Mether L 
Published: January 2024

Abstract
The Future Circular Collider (FCC) study is developing designs for a new research infrastructure to host the next generation of higher performance particle colliders to extend the research currently being conducted at the LHC. In particular, FCC-ee is an electron-positron collider, which is the first stage towards a 100 TeV proton-proton collider FCC-hh. FCC-ee may be affected by electron cloud (e-cloud) and the strongest effects are foreseen for the Z configuration, due to the highest number of bunches, which corresponds to the smallest bunch spacing. The presence of a large electron density in the beam pipe can limit the achievable performance of the accelerator through different effects like transverse instabilities, transverse emittance growth, particle losses, vacuum degradation and additional heat loads of the inner surface of the vacuum chambers. In the design phase, the goal is to suppress the e-cloud effects in FCC-ee and, therefore, a preliminary study to identify the parameters, which play a significant role in the e-cloud formation has been performed. In this paper, an extensive e-cloud simulation study is presented. In particular, the impact of the e-cloud is studied for different configurations, for example: for the electron and the positron beam; in the different elements of the particle accelerator; changing the beam chamber geometry; for different values of the Secondary Emission Yield (SEY); and for different beam parameters.
A novel fiber-optic beam monitor
Authors: Usherovich S. , Casolaro P. , Gottstein A. , Mateu I. , Dehnel M. , Braccini S. , Hoehr C. 
Published: January 2024

Abstract
A novel beam monitor based on Ce-doped silica optical fibers is being presented. Four fibers are mounted on the outside of a beam transport pipe, at the location of a beam stop at a proton cyclotron. The secondary radiation caused by the proton beam interaction with the beam stop is measured by the optical fibers via Radiation-Induced Emission (RIE). The light signal in the individual fibers is correlated to the proton flux closest to the fiber and can therefore be used as a detector to monitor the position of the proton beam in the beam stop. Initial testing shows that monitoring of a 150 nA beam of 18 MeV protons into a beam dump is possible. The monitor can measure relative beam current and beam displacement in X and Y as a function of magnetic steering.
Capacitive BPM electromagnetic design optimisation
Authors: Bilanishvili S. , Zobov M. 
Published: January 2024

Abstract
Capacitive beam position monitors (BPM) are widely used as diagnostics tools in particle accelerators. Typically due to a large number of BPM in an accelerator, their contribution to the beam coupling impedance cannot be neglected. In addition to the broadband part at low frequencies, the impedance exhibits resonant peaks at higher frequencies due to electromagnetic fields trapped around the BPM button and in the feedthrough assembly. Coupling of these peaks with beam spectrum lines can result in the BPM overheating. In this paper, we discuss the BPM design optimization aimed at the beam coupling impedance minimization while keeping the BPM signal transfer impedance.
Bunch-by-bunch transverse position measurement during injection
Authors: Huang Chih-Hsien , Hsu Kuo-Tung , Liao Chih-Yu , Chiu Pei-Chen , Cheng Yung-Sen , Liao Jin-Kun , Hu Kuo-Hwa 
Published: January 2024

Abstract
Bunch-by-bunch systems have been developed at the Taiwan Light Source and the Taiwan Photon Source to monitor transverse position and filling patterns. The system comprises four channels with a 500 MHz sampling rate synchronized with the accelerator’s radio frequency. It is utilized to diagnose injection transients due to kick mismatch, beam oscillations resulting from damped betatron oscillations and wakefield, and monitor the injection current of each bunch.
About the damage mechanisms of thin targets exposed to high-power particle beams
Authors: Sapinski Mariusz 
Published: January 2024

Abstract
Thin targets, in the forms of wires, stripes, or foils, are often used in accelerators to measure the properties of particle beams. Motivations for a small thickness, typically between several and hundred micrometers, are diverse. The minuscule diameter of a wire allows for precision measurement because it is probing a small fraction of the beam’s transverse profile. In case of high-power beams, the important rationale is also a small energy which beam deposits in the target and a good cooling because of a large surface-to-volume ratio. In certain beam conditions, the temperature of the target is still very high and leads to wire damage. This paper presents detailed analysis of ductile breakage of a molybdenum wire and gives a short overview of other damage mechanisms for various materials.
Improvements in longitudinal phase space tomography at PITZ
Authors: Aftab N , Boonpornprasert P , Georgiev G , Good J , Gross M , Hillert W , Hoffmann A , Krasilnikov M , Li X-K , Niemczyk R , Oppelt A , Qian H , Reader A J , Richard C , Stephan F , Vashchenko G 
Published: January 2024

Abstract
Methodical studies to improve the existing e-beam Longitudinal Phase Space (LPS) tomography were performed at the Photo Injector Test facility at DESY in Zeuthen. Proof-of-principle simulations were done to address some core concerns e.g. booster phase range, space charge effects and noisy artefacts in results. Phase advance analysis was done with the help of an analytical model that determined the booster phase range and step size. A slit was introduced before the booster to truncate the beam and reduce space charge forces. The reconstruction method adopted was image space reconstruction algorithm owing to its assurance of non-negative solution. An initial scientific presumption of LPS from low energy momentum measurements was established to reduce artefacts in the phase space. This paper will explain the proof-of-principle simulations highlighting the key aspects to obtain accurate results. Reconstructed LPS for different experimental cases will be presented to demonstrate the diagnostic capability.
Observation of Beam Emittance Reduction due to Gas Sheet Injection for Beam Profile Measurement
Authors: Yamada I , Chimura M , Kamiya J , Kinsho M 
Published: January 2024

Abstract
In a high intensity ion accelerator, a non-destructive beam monitor is required to realize a continuous measurement of the beam for improving the beam quality in operation for users. We have developed a non-destructive 2-D beam profile monitor detecting photons produced by interaction between a beam and a sheet-shaped gas. Though the developed monitor is a non-destructive type, the injected gas sheet should induce scattering of the beam particles which makes the beam emittance large. We have measured a beam current and a phase space distribution of the J-PARC 3 MeV, 60 mA H− beam with change of the gas sheet flux. It was found that the beam current reduction was in linear relation and the root mean square emittance was constant or decreased by up to 4.5% in y-y′ plane and did not change in x-x′ plane against a rise in the gas sheet flux. These result indicate that the developed monitor can be utilized as a non-destructive one depending on the gas sheet flux condition.
Implementation and performance estimation of new archive system for the TLS control system
Authors: Liao J K , Cheng Y S , Hsu L P , Chen J , Hu K H , Hsu K T 
Published: January 2024

Abstract
The TLS (Taiwan Light Source) is a third generation of synchrotron light source that has been operated for more than 25 years, and its control system is a proprietary designed system. The TLS control system maintenance is difficult because of component outage problems. Some parts of the control system are being rejuvenated with the help of the EPICS framework used in the TPS (Taiwan Photon Source) control system to ensure that TLS continues to operate normally, saving both manpower and money. A new EPICS archive system was needed to efficiently record various machine parameters and status information during routine operations. As a result, the EPICS Archiver Appliance has been evaluated as suitable for deploying to archive TLS machine data which encapsulated the PV (Process Variable) channel access. Specific graphical user interfaces and API packages have been supported for quickly retrieving archived data, as well as a plotting function for easy diagnosis. Furthermore, the performance of this new TLS archive system has been estimated, and related system resources will be manually adjusted for better service. The efforts will be summarized in this paper.
New Injection Controls Environment for the Taiwan Light Source
Authors: Chen J , Liao C Y , Wu C Y , Cheng Y S , Liao J K , Hsu K T , Hu K H 
Published: January 2024

Abstract
Taiwan Light Source (TLS) has been service for user service since 1993. Several legacy systems have recently been updated in order to remove obsolescent parts and provide higher operating efficiency. Proprietary designed timing modules were recently replaced by an event based timing system. The magnets of the booster synchrotron were configured as three White circuits and driven by resonance excitation. The original control of the White circuits, which included an analogue amplitude loop and digital phase loop for regulation, has been replaced by full digital regulation loops. The successful upgrade of both systems has led to easy and smooth injection control with enhanced functionality and flexibility. The injection control includes foreground and background processes that coordinate the operation of e-gun, linear accelerator, booster synchrotron, and storage ring with the help of timing system. The injection control GUI provides an intuitive operation interface that includes parameter setting and all necessary information displays, such as various timing value, stored beam current/lifetime, injection efficiency, filling pattern, kickers waveform and so on. Energy saving mode of White circuits operation are supported and embedded into injection control to save electricity. Lifetime calculation of the storage ring is also synchronized with the injection process. Implementation details and operation experience will be presented.
Development of EPICS-Based Data Acquisition system for Beam Loss Monitor and sX-map
Authors: Kuriyama Y. , Iwashita Y. , Fuwa Y. , Hayano H. 
Published: January 2024

Abstract
Beam commissioning is underway at KEK’s Superconducting RF Test Facility (STF). Since beam diagnostics are important to realize stable operation, we have developed a time-resolved beam loss distribution monitor as one of the beam diagnostics. This monitor uses up to 16 PIN photodiodes as X-ray sensors to observe X-rays generated due to beam loss of a pulsed beam with a width of approximately 800 μs, which is divided into 100 μs intervals. Thus, 128 data can be acquired per bunch. The data is read out by an EPICS-based data acquisition system. On the other hand, we are also developing an EPICS-based data acquisition system for an inspection method for the superconducting cavities(sX-map) for the vertical test of bare cavities. sX-map strips are inserted inside the stiffener ring at the iris of superconducting cavities. In this presentation, an overview of these EPICS-based data acquisition systems and their integration with the existing control system will be presented.
Studies of radiation background at the synchrotron light source DELTA
Authors: Khan Shaukat , Mai Carsten , Kebekus Marcel , Schmidt Gerald 
Published: January 2024

Abstract
The 1.5-GeV electron storage ring of the synchrotron radiation source DELTA at TU Dortmund University is surrounded by a 1 m thick concrete radiation shielding wall with a height varying between 3.0 and 4.3 m and with open top. The installation of a new 7-T superconducting wiggler and tentative plans for a new building in the vicinity motivated recent studies of background radiation either directly escaping the open-topped radiation shield or being scattered by air or the roof of the hall (the so-called radiation skyshine). Spectra of gamma radiation were recorded under different conditions using a high-purity germanium detector. Long-term measurements were made with photoluminescence dosimeters. The paper presents the results together with calculations of the spectral distribution of wiggler radiation as well as a model for the spatial distribution of radiation emitted by the whole storage ring.
Upgrades and developments related to stable ion beams injectors at INFN-LNL
Authors: Galatà A , Fagotti E , Francescon P , Gallo C S , Giora D , Martini D , Minarello A , Miglioranza M , Pasquato F , Roetta M , Rossignoli M 
Published: January 2024

Abstract
The LNL accelerator complex is equipped with two stable ion beams injectors, employing respectively negative and positive ion sources. In particular, a sputtering-type negative ion source and an Electron Cyclotron Resonance Ion Source (ECRIS) are installed on high voltage platforms, to provide the optimum injection energy in the downstream accelerators. Recently, the two injectors have been object of upgrades and developments, in order to improve the overall safety and reliability of the two systems, as well as the beams available for the users. This contribution describes the work related to the above-mentioned activities, the technical choices employed and the latest results on ion beams production.
New event based timing system for the Taiwan Light Source
Authors: Wu C Y , Liao C Y , Chen J , Lee D , Cheng Y S , Hu K H , Hsu K T 
Published: January 2024

Abstract
The Taiwan Light Source (TLS) is a third generation synchrotron light source that has been in operation since 1993. However, the legacy timing system is obsolete and needs to be upgraded to an event based timing system. This upgrade is intended to replace obsolete components and improve functionality. The new timing system must coordinate the operation of the linac, the White circuit based booster synchrotron, and the storage ring for beam generation, injection, extraction, and accumulation, while also supporting top up operation of the storage ring. To achieve this, a cPCI (CompactPCI) based EPICS IOC (Input Output Controller) and expandable fanless embedded computers have been adopted for the new TLS timing system, replacing the existing VME-based ILC (Intelligent Local Controller) to provide an easy to maintain control environment. However, the resonant excitation of the booster magnets with the event system requires special attention in the design and implementation phases. This paper summarizes the design ideas and implementation process for addressing this issue.
Preparations of QWR superconducting cavities for beam commissioning
Authors: Kim H , Jung Y , Kim J , Jang H , Kim Y , Gil D , Jeon S , Son K , Lee M , Ki T 
Published: January 2024

Abstract
Quarter-wave resonator (QWR) cavities are prepared for beam commissioning. RF conditioning is performed for each QWR cavity. The total heat load, including static and dynamic heat loads, is measured for each cavity. The helium pressure fluctuation is reduced by changing the flow rate, supply pressure, return pressure, cryogenic valve control, etc. The cavity pressure is monitored during RF preparation. The amplitude and phase of the QWR cavity are stably controlled for beam commissioning.
High-Efficiency Industrial 130 kW cw Solid-State RF Amplifier for 1.3 GHz
Authors: Nedos M , Pupeter N , Wied V , Keune B , Quitmann C , Blokesch G 
Published: January 2024

Abstract
A new 1.3 GHz solid-state high-power RF amplifier (SSA) has been built for the Lighthouse project in close cooperation between Cryoelectra and RI Research Instruments. The amplifier was developed by Cryoelectra as a scalable compact system with an RF-power density of 40kW/m2. Its industrial design is very reliable and easy to maintain. The SSA delivers a continuous RF output power of more than 130 kW with a wall-plug efficiency of 63% and with very low phase noise. The power is generated by 40 patented RF amplifier modules each containing 8 GaN transistor units. Their outputs are combined by a coaxial 8-way combiner in the center of the module. Each module is connected to the 4x9-way cable-free waveguide combiner network and can be exchanged in the event of fault within minutes thanks to quick connectors. A sophisticated control system continuously monitors the state of all components for reliable machine and personnel protection.
Despite all the challenges encountered during development and production, the SSA was built and handed over to the client in the shortest possible time. It passed the acceptance test on site exceptionally well.
New SiC Kicker Power Supply for J-PARC
Authors: Takayanagi T. , Ono A. , Sugita M. , Yamamoto K. , Oguri H. , Kinsho M. , Horino K. , Ueno T. , Oda K. , Tokuchi A. , Ikoma N. 
Published: January 2024

Abstract
A new kicker power supply using silicon carbide metal–oxide semiconductor field-effect transistors (SiC-MOSFETs) is under development at the Japan Proton Accelerator Research Complex (J-PARC). SiC-MOSFETs fabricate compact high-speed pulse power supplies to replace the thyratron switch power supply. The base circuit of the new power supply uses the linear transformer driver (LTD) system, and the semi-conductor module circuit comprises a radial symmetry type that achieves low noise. The three main components of the current kicker power supply, i.e., the thyratron, pulse-forming network (PFN) circuit, and end clipper, can be assembled on a single board as the new module circuit board. The new power supply contains a 1.25 kV/2 kA main board that forms a trapezoidal pulse and a 0.1 kV/2 kA correction board, compensating for the flat section droop. The 32 main boards and 20 correction boards are hierarchically connected in series to achieve the waveform specifications required for the J-PARC rapid cycling synchrotron (RCS) kicker power supply: output voltage of 40 kV, output current of 2 kA, and pulse width of 1.2 μs. Furthermore, a 25 % power saving has been confirmed and an insulating cylinder for the conductor has been developed to suppress corona discharge and withstand continuous operation for a long time.
Finite Element Analysis for NEG coated vacuum chamber based on ANSYS Workbench
Authors: Ma Wenjing , Zhang Wenli , Xu Xiaopeng , Wei Jianya , Wang Sihui , Ge Xiaoqin , Bian Baoyuan 
Published: January 2024

Abstract
The Hefei Advanced Light Facility (HALF) is a diffraction limited storage ring (DLSR) being constructed. As the main component of the storage ring vacuum system, the vacuum chamber transports the beam and withstands the thermal effect of synchrotron radiation simultaneously. The thermal and mechanical condition of the vacuum chamber of HALF were quantitatively analysed by means of ANSYS Workbench in this work. Combining the Computational Fluid Mechanics (CFD) and Finite Elements Analysis (FEA), the temperature and thermal stress maps of the vacuum chamber were calculated. The CFD calculation displays that the heat transfer coefficient between the water and the chamber is 7966-13093 W/(m2·°C). The thermal-mechanical simulation shows that the maximum temperature and thermal stress are 53.5 °C and 42.1 MPa, respectively. The static structural analysis was performed on vacuum chamber under the ultra-high vacuum condition, with the maximum stress of 1.7 MPa and the maximum deformation of 0.0003 mm. These results show that the vacuum chamber meets the design requirements and provide a critical theoretical basis for the design of the vacuum system of HALF.
Vacuum design of the Super-FRS at FAIR
Authors: Kurichiyanil N , Bergmann A , Karagiannis C , Kraemer A , Kurdal J , Mai B , Purushotaman S , Weick H , Winkler M 
Published: January 2024

Abstract
The large-acceptance superconducting fragment separator (Super-FRS) poses unique challenges for its beam and insulation vacuum systems. These systems must operate in high radiation environments and accommodate dynamically changing experimental setups. Although the vacuum levels ranging from 10−5 to 10−7 mbar required by this single-pass machine are not particularly demanding, several factors make the design of the vacuum systems challenging. These include highly outgassing and self-sealing inserts, large volumes not typically encountered in accelerator beamlines, and a high level of prompt and residual radiation in the target and pre-separator area. In this article, an overview of the Super-FRS vacuum design is presented and handling of the standard and special vacuum components in the system is discussed.
Research on hydrostatic leveling system to provide elevation constraints for control network adjustment
Authors: Li X , He X Y , Wang W , Cheng Z B , Wu E C , Zhang Q Y , Ding T 
Published: January 2024

Abstract
As the precise sensor system for monitoring the relative altitude changes among multiple points, the capacity hydrostatic leveling system (HLS) is widely used in particle accelerators. To expand its application in providing the elevation constraint for the control network adjustment, the research on the issue of the HLS for altitude difference measurement between multiple points is carried out. Based on the working principle of the HLS sensor, a comparison system composed of dual-frequency laser interferometer, high-precision Z stage, HLS sensors and others is designed and manufactured. The system is used to control multiple sensors to observe the same liquid level in the same coordinate system. The zero-position difference among sensors can be obtained by comparison. Then the altitude difference measurement can be realized, and it is verified that the measurement accuracy is better than 5 μm. In addition, a simulation experiment for 3D control network measurement is run, in which the HLS system provides the elevation constraint for the adjustment processing. The results show that for the 100m linear tunnel, the errors accumulation in the elevation direction is significantly improved compared to the classics adjustment.