THPOTK —  Poster Session - Tomyam Kung   (16-Jun-22   16:00—18:00)
Paper Title Page
THPOTK001 Variable Permanent Hybrid Magnets for the Bessy III Storage Ring 2763
 
  • J. Völker, V. Dürr, P. Goslawski, A. Jankowiak, M. Titzepresenter
    HZB, Berlin, Germany
 
  The Helmholtz Zentrum Berlin (HZB) is working on the conceptual design of a successor source to BESSY II, an new BESSY III facility, designed for a beam energy of 2.5GeV and based on a multi-bend achromat (MBA) lattice for a low emittances of 100pm-rad. Bending and focusing magnets in the MBA cells should consist of permanent magnets (PM), to allow for a competitive and compact lattice, to increase the magnetic stability and to decrease the electric power consumption of the machine. However, using pure permanent magnet systems would result in a completely fixed lattice. Therefore, we are developing Variable Permanent Hybrid Magnets (VPHM), combining PM materials like NdFeB with a surrounding soft iron yoke and additional electric coils. This design can achieve the same field strength and field quality as conservative magnets, with only a small fraction of the electric power consumption, and a ca. 10% variability in the field amplitudes. In this paper, design and first optimization results of the magnets will be presented, which are a promising option for the new BESSY III facility, and an estimated reduction in total power consumption for the magnet lattice of up to 80%.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK001  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOTK002 Magnet Design for the PETRA IV Storage Ring 2767
 
  • R. Bartolini, I.V. Agapov, A. Aloev, H.-J. Eckoldt, D. Einfeld, B. Krause, A. Petrov, M. Thede, M. Tischer
    DESY, Hamburg, Germany
  • J. Chavanne
    ESRF, Grenoble, France
 
  The proposed PETRA IV electron storage ring that will replace DESY’s flagship synchrotron light source PETRA III will feature a horizontal emittance as low as 20 pmrad. It is based on a hybrid six-bend achromat lattice. In addition to the storage ring PETRA IV, the Booster Synchrotron and the corresponding transfer line will be renewed. Overall about 4000 magnets will be manufactured. The lattice design require high-gradient quadrupoles, which are unfeasible with conventional steel, used traditionally for normal-conducting magnets. The required gradient is safely reached with the poles, made of Permendur. The bending magnets for the storage ring will be based on permanent magnets. This contribution presents the electromagnetic design of the magnets for the storage ring and booster synchrotron.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK002  
About • Received ※ 09 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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THPOTK003 Optimization of Mass Resolution Parameters Combined with Ion Cooler Performance 2770
 
  • M. Cavenago, C. Baltador, L. Bellan, M. Comunian, E. Fagotti, A. Galatà, M. Maggiore, A. Pisent, C.R. Roncolato, M. Rossignoli, A. Ruzzon
    INFN/LNL, Legnaro (PD), Italy
  • G. Maero, M. Romé
    Universita’ degli Studi di Milano e INFN, Milano, Italy
  • V. Varialepresenter
    INFN-Bari, Bari, Italy
 
  High mass resolution spectrometers (HRMS) for separation of exotic ion species in nuclear physics experiment request a low emittance and small energy spread (with D E the peak-to-peak value, and sE the rms value) of the input beam, so that ion cooler devices, as a Radio Frequency Quadrupole Coolers (RFQC), are typically envisioned. The SPES (Selective Production of Exotic Species) project at LNL requests M/(D M) about 20000, rms normalized emittance in the order of 2 nm, and for 160 keV ions, spread sE about 1 eV. Typical limits of RFQC[*] and HRMS[**] performances are discussed, and relevant formulas are implemented in easy reference tools. The necessary collisional data are reviewed, in particular for Cs+ against He gas, whose pressure ranges from 2 to 9 Pa; status of Milan test bench is briefly updated. Practical consideration on gas pumping, voltage stability and magnet design are also included.
[*] Cavenago et al. Optimization of ion transport in a combined RFQ Cooler …, in ICIS 2021 (in press)
[**] M. Comunian et al. p. 3252 in proceedings IPAC2018 doi:10.18429/JACoW-IPAC2018-THPAK021
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK003  
About • Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOTK004 The Reduction of the Leakage Field of the Injection Septum Magnet in Main Ring of J-PARC 2774
 
  • T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto
    KEK, Ibaraki, Japan
 
  A new injection septum magnet (InjSep) was installed in MR in 2016 for one of the upgrading of beam power of MR. We have measured the leakage field before installation, and it was found from the measurement results that the leakage field at the beam upstream region of the circulating duct was enough smaller than previous InjSep, however we tried to reduce the leakage field further by installation a new magnetic shield. First magnetic shield was produced in 2017, and we installed it in the InjSep. The leakage field was reduced, however the magnetic field of a quadrupole magnet at beam upstream of the InjSep was also reduced slightly. The decrease of the magnetic field of the one of main magnet was not permitted from the requirement of beam optics. In consequently, the first version was failed. The second one was produced in 2018, and we measured the leakage field was measured in Jan. 2019. The leakage field was reduced, while no reduction of the quadrupole magnet. We decided to use the second version for beam operation. The new additional shield was started to use in Nov. 2019.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK004  
About • Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 13 June 2022
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THPOTK005 The New High Field Septum Magnet for Upgrading of Fast Extraction in Main Ring of J-PARC 2778
 
  • T. Shibata, K. Ishii, S. Iwata, H. Matsumoto, N. Matsumoto, T. Sugimoto
    KEK, Ibaraki, Japan
  • K. Fan
    HUST, Wuhan, People’s Republic of China
 
  Upgrading the beam-power of the J-PARC Main Ring to 750 kW is underway by reducing the cycle from 2.48 s to 1.3 s. Required upgrade of the four High Field (HF) Septa will be completed in 2022. The operation test of a new HF SM31 was conducted in 2020. First was 1 Hz operation test. The power supply had no problem in the operation, and the joule heating at the magnet coil was lower than limit. We found a good linearity between the current and the gap field which has no saturation. The field integral in the magnet gap was measured to calculate the appropriate current for beam operation, and we found it was 3,400 A. We compared the gap field of the neutrino side with that of the beam abort side. The magnitude of gap field had no significant discrepancy larger than its measurement accuracy. The end-fringe field was measured and the we found large leakage field still existed around the end-fringes. We are producing an additional magnetic shield which will be mounted in the circulating beam duct, and it will finished in Feb. 2022. In next March we will install the inner shield and measured the leakage field. After that we will install the new SM31 in MR.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK005  
About • Received ※ 20 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 28 June 2022
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THPOTK007 Magnet Systems for Korea 4GSR Light Source 2781
 
  • D.E. Kim, T. Ha, G. Hahn, Y.G. Jung, H.-G. Lee, J. Lee, S. Shin, H.S. Suh
    PAL, Pohang, Republic of Korea
 
  Funding: Work supported by NRF of the Republic of Korea.
A 4th generation storage ring based light source is being developed in Korea since 2021. It features < 100 pm rad emittance, about 800 m circumference, 4 GeV e-beam energy, full energy booster injection, and more than 40 beamlines which includes more than 24 insertion device (ID) beamlines. This machine requires about ~1000 magnets including dipole, longitudinal gradient dipole, transverse gradient dipole, sextupoles, and correctors. The apertures are small and the lattice space requirements are very tight. In this report, a preliminary design of the each magnet is presented with detailed plan for the future.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK007  
About • Received ※ 13 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 07 July 2022  
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THPOTK009 Design of a Permanent Magnet Based Dipole Quadrupole Magnet 2784
 
  • A.G. Hinton
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • M. Kokole, T. Milharčič
    KYMA, Trieste, Italy
  • A. Shahveh
    DLS, Oxfordshire, United Kingdom
  • B.J.A. Shepherd
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • B.J.A. Shepherd
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Permanent magnet technology can facilitate the design of accelerator magnets with much lower power consumption than traditional resistive electromagnets. By reducing the power requirements of magnets, more sustainable accelerators can be designed and built. At STFC, as part of the I.FAST collaboration, we are working to develop sustainable technologies for future accelerators. As part of this work, we have designed a permanent magnet based dipole-quadrupole magnet with parameters suited to meet the requirements of the proposed Diamond-II upgrade. We present here the magnetic design of the dipole-quadrupole magnet. The design, based on a single sided dipole-quadrupole, uses permanent magnets to generate the field in the magnet bore. The design includes the shaping of the pole tips to reduce multipole errors as well as methods of providing thermal stabilisation using thermal shunts and field tuning using resistive coils. The mechanical design of the magnet is being undertaken by colleagues at Kyma and a prototype of the magnet will soon be built and tested.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK009  
About • Received ※ 06 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 06 July 2022  
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THPOTK010 Development of a Short Period Superconducting Helical Undulator 2788
 
  • A.G. Hinton
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • J. Boehm, L. Cooper, B. Green, T. Hayler, P. Jeffery, C.P. Macwaters, B.J.S. Matthews
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • S. Milward
    DLS, Oxfordshire, United Kingdom
  • B.J.A. Shepherd, N. Thompson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Superconducting technology provides the possibility to develop short period, small bore undulators that can generate much larger magnetic fields than alternative technologies. This may allow an XFEL with optimised superconducting undulators to cover a broader range of wavelengths than traditional undulators. At STFC, we have undertaken work to design and build a prototype superconducting helical undulator module with parameters suitable for use on a future XFEL facility. This work includes the design of an undulator with 13 mm period and 5 mm magnetic gap, as well as the supporting cryogenic and vacuum systems required for operation. We present here the updated design of the superconducting helical undulator that represents the results of prototyping work. Improved methods for manufacturing the undulator former and winding the superconducting wire have been developed. The measured mechanical tolerances and the impact on the field quality will be presented. The fields produced by prototype undulators will soon be measured using a Hall probe system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK010  
About • Received ※ 06 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 17 June 2022  
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THPOTK011 Permanent Magnets for the CEBAF 24GeV Upgrade 2792
 
  • S.J. Brooks
    BNL, Upton, New York, USA
  • S.A. Bogacz
    JLab, Newport News, Virginia, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An upgrade of the CEBAF facility to double its present energy of 12GeV has been proposed. To provide double the number of linac passes using the existing five stacked arc beamlines, some beamlines are replaced by fixed-field accelerator (FFA) arcs, allowing multiple energies to pass through the same magnets. A solution is presented in which two of the existing electromagnetic beamlines are replaced with permanent magnet non-scaling FFA arcs, as demonstrated at CBETA. The two-stage design reduces peak magnetic field and synchrotron radiation loss compared to using a single stage. FFAs do not pulse their magnets, making permanent magnets a promising and power-efficient technology option. However, the magnetic field requirements are still at the high end of accelerator permanent magnets produced thus far (1.6T peak on beam), while the magnets must also be combined-function, having a gradient with a dipole offset. Designs using a novel oval aperture and open midplane within an adapted Halbach magnet are presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK011  
About • Received ※ 31 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 04 July 2022
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THPOTK013 Cold Test Results of the FAIR Super-FRS First-of-Series Multiplets and Dipole 2796
 
  • A. Chiuchiolo, A. Beaumont, E.J. Cho, F. Greiner, P. Kosek, M. Michels, H. Müller, C. Roux, H. Simon, K. Sugita, V. Velonas, F. Wamers, M. Winkler, Y. Xiang
    GSI, Darmstadt, Germany
  • H. Allain, V. Kleymenov, A. Madur
    CEA-IRFU, Gif-sur-Yvette, France
 
  Within the collaboration between GSI and CERN, a dedicated cryogenic test facility has been built at CERN (Geneva, Switzerland) in order to perform the site acceptance tests of the 56 Superconducting FRagment Separator cryomodules before their installation at the the Facility for Antiproton and Ion Research (Darmstadt, Germany). Two of the three benches of the CERN test facility were successfully commissioned with the powering tests of the first-of-series multiplets and dipole. The long multiplet, with a warm bore radius of 192 mm, is composed of nine magnets of different type (quadrupole, sextupole, steering dipole and octupole) assembled with Nb-Ti racetrack and cosine-theta coils, mounted in a cold iron yoke and in a common cryostat. This work presents the first results of the cold powering tests at 4.5 K during which dedicated measurements have been implemented for the magnetic characterization of the single magnets up to nominal current (300 A for a long quadrupole) and the study of their crosstalk effects. The results of the acceptance tests will be presented together with the challenges and lessons learnt during the facility commissioning.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK013  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022
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THPOTK014 100 keV Electron Source Design for the New 3 GeV Synchrotron Facility in Thailand 2800
 
  • N. Juntong, S. Bootiew, T. Chanwattana, Ch. Dhammatong, S. Jummunt, K. Kittimanapun, W. Phacheerak
    SLRI, Nakhon Ratchasima, Thailand
  • K. Manasatitpong
    Synchrotron Light Research Institute (SLRI), Muang District, Thailand
 
  The Synchrotron Light Research Institute (SLRI) is developing a new synchrotron light source with an electron beam energy of 3 GeV. The DC thermionic electron gun was chosen because it is simple and less cost. The design process is well known. The operation is more stable compared to the RF gun. The cathode Y-646B was considered because it had already been used at the old synchrotron machine and the possibility of sharing the stock outweighs other disadvantages. Moreover, it is used in many synchrotron facilities, so it is easy to find references. The present of the focusing electrode was discussed. The focusing electrode will increase the complexity of the gun, but it is necessary to get a high-quality beam from the gun. The designed electron gun can produce 1.1 A beams current with the normalized emittance of 0.910 Pi·mm·mrad, which satisfied the requirement of the linac injector. The design and study results will be discussed in this report.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK014  
About • Received ※ 20 May 2022 — Accepted ※ 14 June 2022 — Issue date ※ 29 June 2022  
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THPOTK015 Solid-State Pulsed Power Supply for a 100 keV Electron Source of the New Synchrotron Facility in Thailand 2803
 
  • W. Phacheerak, S. Bootiew, T. Chanwattana, Ch. Dhammatong, N. Juntongpresenter, K. Kittimanapun
    SLRI, Nakhon Ratchasima, Thailand
  • K. Manasatitpong
    Synchrotron Light Research Institute (SLRI), Muang District, Thailand
 
  The new synchrotron light source project in Thailand will utilize a thermionic DC electron gun. The maximum operation of the gun is 100 keV, which requires a pulsed power supply of 100kV. The present synchrotron machine uses a conventional design of the gun power supply. To improve the high voltage pulsed quality, the solid-state design of the gun power supply is utilized. The output pulse width can be adjusted easily and the droop is less compared to the conventional design. The designed output of 100 kV amplitude with 5 µs pulsed width can be achieved with this design. It also produces a less droop of 1.8%. The design process and results will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK015  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
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THPOTK019 Collider NICA Power Supply Magnet System 2806
 
  • V. Karpinsky, R.M. Ahmadrizyalov, S.A. Arefev, A.V. Butenko, A.V. Karavaev, S.V. Kirov, A.V. Kopchenov, A.A. Kozlykovskaya, T.A. Kulaeva, A.L. Osipenkov, A.V. Sergeev, A.A. Shurygin, E. Syresinpresenter, V.G. Tovstuha, N.V. Travin
    JINR, Dubna, Moscow Region, Russia
  • M.I. Kuznetsov
    JINR/VBLHEP, Dubna, Moscow region, Russia
 
  A power supply system for Collider structural magnets is considered, which consists of precision current sources, energy evacuation devices for superconducting elements, additional sources, and control and monitoring equipment. The status of the equipment and the plan of its placement in Collider bld. 17 are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK019  
About • Received ※ 02 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022  
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THPOTK020 Recent Experience from the Large-Scale Deployment of Power Converters with Magnet Energy Recovery 2809
 
  • K.D. Papastergiou, G. Le Godec, V. Montabonnet
    CERN, Meyrin, Switzerland
 
  A new powering solution was deployed at CERN for transfer lines in the injector complex as part of the LHC injectors upgrade. The new powering uses regenerative power converters to recycle the magnet energy between physics operations. This work gives an overview of the developed technology, the way it is used in the accelerators complex and some results of first period of operation with beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK020  
About • Received ※ 03 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 28 June 2022
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THPOTK022 Cryogenic Infrastructure for the Mainz Energy-Recovering Superconducting Accelerator (MESA) 2813
 
  • T. Stengler, K. Aulenbacher, F. Hug, P.S. Plattnerpresenter, D. Simon
    KPH, Mainz, Germany
 
  Funding: Work supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019
The "Mainz Energy-Recovering Superconducting Accelerator" (MESA), currently under construction at the Institute of Nuclear Physics, Johannes Gutenberg University Mainz, Germany, requires a cryogenic infrastructure for its superconducting components. Prior to the start of the project, a helium liquefier was purchased that is capable of supplying the existing infrastructure of the Institute for Nuclear Physics, as well as the SRF test facility of the Helmholtz Institute. The liquefier has already been purchased in such a way that nitrogen pre-cooling can be integrated and can be upgraded for the operation of MESA. In addition to the superconducting accelerator modules, all components of the P2 experiment, i.e. solenoid, target and polarimeter (hydromoller), must also be supplied with liquid helium. Therefore, besides the upgrade of the liquefier, it is necessary to extend the system with a dedicated cryogenic supply for the P2 target. This paper presents the current status of the cryogenic supply of the MESA accelerator, the future modifications and additions.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK022  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022
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THPOTK023 Ferrite Specification for the Mu2e 300 kHz and 4.4 MHz AC Dipole Magnets 2816
SUSPMF116   use link to see paper's listing under its alternate paper code  
 
  • K.P. Harrig, E. Prebys
    UCD, Davis, California, USA
  • L. Elementi, C.C. Jensen, H. Pfeffer, D.A. Still, I. Terechkine, S.J. Werkema, M. Wong
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work supported by by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, in addition to grant DE-SC0019254.
The Mu2e experiment at Fermilab will measure the rate for neutrinoless-conversion of negative muons into electrons with never-before-seen precision. This experiment will use a pulsed 8 GeV proton beam with pulses separated by 1.7 µs. To suppress beam induced backgrounds to this process, a set of dipoles operating at 300 kHz and 4.4 MHz have been developed that will reduce the fraction of out-of-time protons at the level of 1E-10 or less. Selection of magnetic ferrite material for construction must be carefully considered given the high repetition rate and duty cycle that can lead to excess heating in conventional magnetic material. A model of the electromagnetic and thermal properties of candidate ferrite materials has been constructed. Magnetic permeability, inductance, and power loss were measured at the two operating frequencies in toroidal ferrite samples as well as in the ferrites from which prototype magnets were built. Additionally, the outgassing rates of the ferrite material was measured to determine vacuum compatibility. The outcome of this work is a detailed specification of the electrical and mechanical details of the ferrite material required for this application.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK023  
About • Received ※ 30 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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THPOTK025 Heat Loads Measurement Methods for the ESS Elliptical Cryomodules SAT at Lund Test Stand 2819
 
  • N. Elias, X.T. Su
    ESS, Lund, Sweden
  • W. Gaj, P. Halczynski, M. Sienkiewicz, F.D. Skalka
    IFJ-PAN, Kraków, Poland
 
  The Site Acceptance Testing of all ESS elliptical cryomodules is done at Lund Test Stand. The cryogenic heat loads (static and dynamic) are an essential part of the acceptance criteria. We present complementary measurement methods for evaluating the cryogenic heat loads and discuss a qualitative comparison between them. We also present a summary of the results of these methods for one of the cryomodules.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK025  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
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THPOTK026 Development and Test of a Program for Automatic Conditioning of Room Temperature Cavities 2823
 
  • K. Kümpel, M. Märcz, H. Podlech, A. Rüffer, C. Wagner, S.R. Wagner
    IAP, Frankfurt am Main, Germany
  • H. Podlech
    HFHF, Frankfurt am Main, Germany
 
  The conditioning of room temperature cavities is a time-consuming process that can take several weeks and requires the supervision of experienced experimenters. To simplify this process for future cavities, a program is currently being developed at the IAP Frankfurt that will simplify the experimenter’s work and eventually take it over completely. This paper describes the basic setup of the program so far, as well as the tests performed on different cavities so far. In addition, an outlook for the next development steps and their application is given.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK026  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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THPOTK027 Temperature Dependent Effects on Quality Factor in C-band RF Cavities 2826
 
  • J.R. Parsons, A. Fukasawa, G.E. Lawlerpresenter, N. Majernik, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
 
  Funding: This work was supported by DOE Contract DE-SC0020409
Cryogenic operation and associated skin effects are encouraging fields of study for increasing RF gradients of beams within cavities and decreasing the required size for linear accelerators such as free electron lasers. Notably, a cavity’s RF quality factor Q, the ratio of the outgoing RF signal power to the input power, is theoretically multiplied by over 4 when subjected to cryogenic temperatures. Precise measurements of this Q factor require defining a cryostat unit, which consists of a high vacuum chamber, a coldhead, and MLI shielding. We optimized the cryostat by running several cool down tests at high vacuum, incorporating different geometries of MLI shielding to achieve the lowest possible temperatures. We then performed a low power C-band test after installing a cylindrical copper RF cavity to measure the Q factor. Finally, we improved stability and amplification within the chamber by installing edge welded bellows to the coldhead to reduce vibrations. These measurements provide a basis for the development of cryogenic infrastructure to sustain a cryogenic temperature environment for future RF applications.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK027  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 27 June 2022
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THPOTK029 Role of Surface Chemistry in Conditioning of Materials in Particle Accelerators 2829
 
  • G. Sattonnay, S. Bilgen, S. Della Negra, D. Longuevergne, B. Mercier, I. Ribaud
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
 
  For the vacuum scientists and the accelerator community, finding solutions to mitigate pressure rises induced by electron, photon and ion desorption and beam instabilities induced by ion and electron clouds is a major issue. Along the time, changes in the surface chemistry of vacuum chambers are observed during beam operations in particle accelerators, leading to modifications of: outgassing rates, stimulated desorption processes and a decrease of secondary emission yields (SEY). To understand the role of the surface chemistry of air exposed materials in the electron conditioning process, typical air exposed materials used in particle accelerators : thin film coatings (NEG and TiN), copper (and its oxides Cu2O and CuO) and Niobium were conditioned by low energy electron irradiation for a better understanding of Ecloud effect. First, SEY was measured to understand the changes of surface conditioning upon particle irradiation; then, surface chemistry evolution after electron irradiation was investigated by both XPS and TOF-SIMS analyses using the ANDROMEDE facility at IJCLab. Finally, the relationship between the surface chemistry and the conditioning phenomenon will be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK029  
About • Received ※ 20 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 05 July 2022
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THPOTK032 A Vacuum System for the Milliampere Booster 2833
 
  • R.G. Heine, C.L. Loreypresenter
    KPH, Mainz, Germany
 
  The Milliampere Booster (MAMBO) is the injector linac for the Mainz Energy-recovering Superconducting Accelerator MESA. MESA is a multi-turn energy recovery linac with beam energies in the 100 MeV regime currently designed and built at Institut für Kernphysik (KPH) of Johannes Gutenberg-Universität Mainz. The main accelerator consists of two superconducting Rossendorf type modules, while the injector MAMBO relies on normal conducting technolgy. The MAMBO RF cavities are bi-periodic pi/2 structures that are about 2m long, each. In this paper we present the results of Molflow+ simulations of several setups of the vacuum system for MAMBO that differ in number of pumps, pumping speed and diameter of the pumping ports that are connected to the DN40 beam pipe.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK032  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 24 June 2022
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THPOTK034 Vacuum System Performance of the 3 GeV Electron Storage Ring at MAX IV Laboratory 2836
 
  • M.J. Grabski, E. Al-Dmour, S.M. Scolari
    MAX IV Laboratory, Lund University, Lund, Sweden
 
  The 3 GeV electron storage ring at MAX IV laboratory is the first synchrotron light source with compact multi-bend achromat (MBA) magnet lattice to achieve ultra-low emittance. The vacuum system of the accelerator is fully coated with non-evaporable getter (NEG) thin film to ensure low gas density. The storage ring started commissioning in August 2015 and currently delivers photon beams from insertion devices (IDs) to 9 beamlines that are in user operation or commissioning. After over 6 years of operation, the NEG coated vacuum system continues to be reliable, is conditioning well and do not pose any limitation to the accelerator operation. The average dynamic pressure is lower than the design value (below 3·10-10 mbar) and is reducing with the accumulated beam dose. The vacuum beam lifetime is greater than 39 Ah, and the total beam lifetime is above the design value of 5 Ah - thus is not limited by the residual gas density. Several successful interventions to install new vacuum components were performed on few achromats in the storage ring during shutdowns. Some of them were done utilizing purified neon gas to vent the vacuum system, thus avoiding the need of re-activation of the NEG coating and saving intervention time without compromising the storage ring performance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK034  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 28 June 2022
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THPOTK035 Thermo-Mechanical Modeling and Thermal Performance Analysis of Beam Vacuum Line Interconnections and Cold Warm Transitions in HL-LHC Long Straight Section Magnets 2839
 
  • J. Harray, C. Garion, V. Petitpresenter
    CERN, Meyrin, Switzerland
 
  The HL-LHC upgrade, aiming at increasing the LHC levelled luminosity by factor of five, relies on new superconducting magnets requiring a new beam vacuum system. Along with the challenges related to magnet design, the beam optic configuration exposes this new equipment to stringent conditions for vacuum and cryogenic performance. Both cold-warm transitions and magnet interconnections appear to be delicate components that are crucial for the thermal heat transfer between diverse subsystems. The proposed study aims at assessing the heat loads to the cryogenic system and the temperature fields in the vacuum system. A nonlinear static thermal analysis is first performed. A thermo-mechanical approach is developed to capture additional thermal resistance arising from contact between components and their behaviour during cool-down. The system is then studied under dynamic operations when beams are circulating and colliding. A thorough analysis of beam-induced heat loads under ultimate conditions highlights the different relevant contributions. Finally, the transient response of the systems is computed to assess thermal time constants.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK035  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 29 June 2022
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THPOTK036 Determination of Pumping and Dynamic Vacuum Properties of Conductive Quaternary Alloy of TiZrVAg Non-Evaporable Getter. 2843
 
  • R. Valizadeh, A.N. Hannah, O.B. Malyshev
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • G.Y. Hsiung
    NSRRC, Hsinchu, Taiwan
  • J.M. O’Callaghan Castella
    Universitat Politécnica de Catalunya, Barcelona, Spain
  • M. Pont, N.D. Tagdulang
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  Non Evaporable Getter (NEG) coating has been employed extensively in the particle accelerator especially where the vacuum conductance of the vessel is severely restricted and ultra-high vacuum condition is required. NEG coating will significantly reduce the outgassing rate and provides active pumping surface for H2, CO and CO2. In addition, it has been proven that NEG coated surfaces have a very low secondary electron yield, as well as low photon and electron stimulated desorption yields. However, the existing NEG film increases the RF surface resistance of the beam pipe. In order to increase NEG coating conductivity, at ASTeC, in the past several years, the alternative NEG com-position have been studied by adding more conductive element such as Cu, Au, Al and Ag. In this study, we report on the photon stimulated desorption, activation temperature and surface resistance from room temperature to cryogenic temperature for a new NEG quaternary alloy of TiVZrAg as function of the film composition.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK036  
About • Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOTK037 Measurement of the Photon Stimulated Desorption for Various Vacuum Tubes at a Beam Line of TLS 2847
 
  • G.Y. Hsiung, C.M. Cheng
    NSRRC, Hsinchu, Taiwan
  • R. Valizadehpresenter
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  For most light sources, the synchrotron radiation (SR) hit on the beam ducts or absorbers results in higher pressure rise and the consequent higher radiation level through the commissioning stage. Various surface treatments, e.g. chemical cleaning, oil-free machining, NEG-coating, etc., for the beam ducts or absorbers have been developed worldwide for mitigating the yield of Photon Stimulated Desorption (PSD). A beam line, BL19B, of 1.5 GeV Taiwan Light Source (TLS) has been modified to measure the PSD-yield of the vacuum tubes. The white light of BL19B covers the critical length at 2.14 keV is suitable for generating higher yield of the photo-electrons (PEY) and the consequent PSD-yield to be measured can be resolved wide range of 10-2 ~ 10-7 molecules/photon. The PSD-outgas, measured by RGA, contains the typical H2, CO, CO2, hydrocarbons, and Kr from NEG-coating, alcohol from ethanol machined surface, in some cases. The effect of beam-cleaning reflects the PSD-molecules generated from the SR-irradiated surface. The comparison of the PSD for the various vacuum tubes will be described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK037  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 08 July 2022
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THPOTK038 Electron Stimulated Desorption From Titanium Tube 2850
 
  • O.B. Malyshev, R. Valizadehpresenter
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Titanium is one of material that used for production of accelerator vacuum chamber and components. In this paper we report the results of vacuum properties evaluation measurements of titanium vacuum chamber. The sample was produced from 40-mm inner diameter tube made of titanium and equipped with CF40 flanges at both ends. The electron stimulated desorption (ESD) was measured after 24-h bakeout to 80, 150, 180 and 250 oC. H2 and CO initial sticking probabilities were measured after bakeout before the ESD measurements. After ESD measurements, the initial H2 and CO sticking probabilities were measured again together with CO sorption capacity. These measurements provide the results for ESD as a function of electron dose baked to different temperatures and demonstrate the efficiency of electron stimulated activation of titanium vacuum chamber.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK038  
About • Received ※ 25 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOTK039 The Effect of Activation Duration on the Performance of Non-Evaporable Getter Coatings 2854
 
  • E.A. Marshall, O.B. Malyshev, R. Valizadehpresenter
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Non-evaporable getter (NEG) coatings can be activated at temperatures as low as 140°C. However, better pumping properties are achieved using higher temperatures, between 150-300 °C. This paper investigates whether using an increased activation duration can improve the NEG properties obtained using lower activation temperatures, and so decrease the energy and temperature requirement. This could allow a greater range of materials to be used in particle accelerator systems. Our findings have shown that increasing activation duration from 24 hrs to 1 week at 160 °C produces an improvement in the NEG pumping properties.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK039  
About • Received ※ 01 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 17 June 2022  
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THPOTK040 Few-Nanosecond Stripline Kickers for Top-Up Injection into PETRA IV 2858
 
  • G. Loisch, V. Belokurov, F. Obier
    DESY, Hamburg, Germany
 
  PETRA IV is the planned ultralow-emittance upgrade of the PETRA III synchrotron light source at DESY, Hamburg. The current baseline injection scheme is an off-axis, top-up injection with few-nanosecond stripline kickers, which would allow for accumulation and least disturbance of experiments during injection. Besides the requirements on kick-strength, field quality, pulse rise-rate, and heat management, two mechanical designs with different apertures are necessary, as the devices will be used for injection and the transverse multi-bunch feedback system. In this contribution we will present the current status of 3D finite element simulations of electromagnetic fields and heating as well as the mechanical design and first pulse electronics tests.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK040  
About • Received ※ 20 May 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 29 June 2022
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THPOTK041 Development of Programmable Bipolar Multi kHz Kicker Drivers for Long Pulse Superconducting Electron Linacs 2862
 
  • J.L. Teichgräber, W. Decking, J. Kahl, F. Obier
    DESY, Hamburg, Germany
 
  Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany Superconducting cavities allow for long rf-pulses, which enable the acceleration of thousands of electron bunches within one rf-pulse. Due to transient effects, e.g. coupler kicks, eddy currents or wakefields, bunch properties like the beam trajectory can change along the pulse train. To compensate for this, kicker systems based on high-current operational amplifiers have been developed for the free electron lasers European XFEL and FLASH at DESY in Hamburg. Here, we present the layout of the kicker system, the setup of the pulse electronics, and operational results with beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK041  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022
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THPOTK042 Non-Linear Phenomena Studies in High-Gradient RF Technology for Hadrontherapy at IFIC 2865
SUSPMF117   use link to see paper's listing under its alternate paper code  
 
  • P.M.R. Martinez-Reviriego, C. Blanch Gutiérrez, D. Esperante Pereira, J. Fuster, N. Fuster-Martínez, B. Gimeno, D. Gonzalez-Iglesias, P. Martín-Luna
    IFIC, Valencia, Spain
 
  High-Gradient accelerating cavities are one of the main research lines in the development of compact linear colliders. However, the operation of such cavities is currently limited by non-linear effects that are intensified at high electric fields, such as dark currents and radiation emission or RF breakdowns. A new normal-conducting High Gradient S-band Backward Travelling Wave accelerating cavity for medical application (v=0.38c) designed and constructed at CERN is being tested at IFIC. In this paper, we present experimental measurements and simulation of such non-linear effects. The main goal of these studies is to establish the viability of using these techniques in linear accelerators, in order to improve our understanding in such effects. The main goal of these studies is to determine the viability of using this techniques in linear accelerators for hadrontherapy treatments in hospitals.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK042  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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THPOTK043 Mitigation of High Voltage Breakdown of the Beam Screen of a CERN SPS Injection Kicker Magnet 2868
 
  • M.J. Barnes, W. Bartmann, M. Díaz Zumel, L. Ducimetière, L.M.C. Feliciano, T. Kramer, V. Namora, T. Stadlbauer, D. Standen, P. Trubacova, F.M. Velottipresenter, C. Zannini
    CERN, Meyrin, Switzerland
 
  The SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam induced power deposition was considered an issue. These magnets are very lossy from a beam impedance perspective: this is expected to be an issue during SPS operation with the higher intensity beams needed for HL-LHC. A design, with serigraphy applied to an alumina carrier, has been developed to significantly reduce the broadband beam coupling impedance and hence mitigate the heating issues. During high voltage pulse testing there were electrical discharges associated with the serigraphy. Detailed mathematical models have been developed to aid in understanding the transiently induced voltages and to reduce the magnitude and duration of electric field. In this paper, we discuss the solutions implemented to mitigate the electrical discharges while maintaining an adequately low beam-coupling impedance. In addition, the results of high voltage tests are reported. The alumina substrate has a high secondary electron yield and thus electron-cloud could be an issue, with SPS beam, if mitigating measures were not taken: this paper also discusses the measures implemented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK043  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
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THPOTK044 Ultra-Fast Generator for Impact Ionization Triggering 2872
 
  • A.A. del Barrio Montañés, Y. Dutheilpresenter, T. Kramer, V. Senaj
    CERN, Meyrin, Switzerland
  • M. Sack
    KIT, Karlsruhe, Germany
 
  Impact ionization triggering can be successfully applied to standard thyristors, thus boosting their dI/dt capability by up to 1000x. This groundbreaking triggering requires applying significant overvoltage on the anode-cathode of thyristor with a slew rate > 1kV/ns. Compact pulse generators based on commercial off-the-shelf (COTS) components would allow the spread of this technology into numerous applications, including fast kicker generators for particle accelerators. In our approach, the beginning of the triggering chain is a HV SiC MOS with an ultra-fast super-boosting gate driver. The super boosting of a 1.7kV rated SiC MOS allows to reduce the MOS rise time by a factor of > 25 (datasheet tr = §I{20}{ns} vs. measured tr < 800ps, resulting in an output voltage slew rate > 1kV/ns and an amplitude > 1kV. Additional boosting is obtained by a Marx generator with GaAs diodes, reaching an output voltage slew rate > 11kV/ns. The final stage will be a Marx generator with medium size thyristors triggered in impact ionization mode with sufficient voltage and current rating necessary for the triggering of a big thyristor. This paper presents the impact ionization triggering of a small size thyristor.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK044  
About • Received ※ 16 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 06 July 2022
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THPOTK045 Branch Module for an Inductive Voltage Adder for Driving Kicker Magnets with a Short Circuit Termination 2875
 
  • J. Ruf, M.J. Barnes, Y. Dutheilpresenter, T. Kramer
    CERN, Meyrin, Switzerland
  • M. Sack
    KIT, Karlsruhe, Germany
 
  For driving kicker magnets terminated in a short circuit, a branch module for an inductive voltage adder has been designed and assembled. The module has been designed for a maximum charging voltage of 1.2 kV and an output current of 200 A considering the current doubling due to the short circuit termination. It features three consecutive modes of operation: energy injection, freewheeling, and energy extraction. Therefore, the topology of the branch module consists of two independently controlled SiC MOSFET switches and one diode switch. In order not to extend the field rise time of the kicker magnet significantly beyond the magnet fill time, the pulse must have a fast rise time. Hence, the switch for energy injection is driven by a gate boosting driver featuring a half bridge of GaN HEMTs and a driving voltage of 80 V. Measurements of the drain source voltage of this switch showed a fall time of 2.7 ns at a voltage of 600 V resulting in a voltage rise time of 5.4 ns at the output terminated with a resistive load. To meet both the rise time and current requirements, a parallel configuration of four SiC MOSFETs was implemented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK045  
About • Received ※ 16 May 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022  
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THPOTK048 Radiation Load Studies for the FCC-ee Positron Source with a Superconducting Matching Device 2879
SUSPMF118   use link to see paper's listing under its alternate paper code  
 
  • B. Humann
    TU Vienna, Wien, Austria
  • B. Auchmann, J. Kosse
    PSI, Villigen PSI, Switzerland
  • I. Chaikovska, S. Ogur
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • B. Humann, A. Latina, A. Lechner, Y. Zhao
    CERN, Meyrin, Switzerland
 
  For an electron-positron collider like FCC-ee, the production of positrons plays a crucial role. One of the design options considered for the FCC-ee positron source employs a superconducting solenoid made of HTS coils as an adiabatic matching device. The solenoid, which is placed around the production target, is needed to capture positrons before they can be accelerated in a linear accelerator. A superconducting solenoid yields a higher peak field than a conventional-normal conducting magnetic flux concentrator, therefore increasing the achievable positron yield. In order to achieve an acceptable positron production, the considered target is made of tungsten-rhenium, which gives also a significant flux of un-wanted secondary particles, that in turn could generate a too large radiation load on the superconducting coils. In this study, we assess the feasibility of such a positron source by studying the heat load and long-term radiation damage in the superconducting matching device and surrounding structures. Results are presented for different geometric configurations of the superconducting matching device.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK048  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
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THPOTK049 Irradiation of Low-Z Carbon-Based Materials with 440 GeV/c Proton Beam for High Energy & Intensity Beam Absorbers: The CERN HiRadMat-56-HED Experiment 2883
 
  • P. Andreu Muñoz, M. Calviani, N. Charitonidis, A. Cherif, E.M. Farina, A.M. Krainer, A. Lechner, J. Maestre, F.-X. Nuiry, R. Seidenbinder, C. Torregrosa
    CERN, Meyrin, Switzerland
  • P. Simon
    TU Darmstadt, Darmstadt, Germany
 
  The beam stored energy and the peak intensity of CERN Large Hadron Collider (LHC) will grow in the next few years. The former will increase from the 320 MJ values of Run2 (2015-2018) to almost 540 MJ during Run3 (2022 onwards) and 680 MJ during the HL-LHC era putting stringent requirements on beam intercepting devices, such as absorbers and dumps. The HiRadMat-56-HED (High-Energy Dumps) experiment performed in Autumn 2021 executed at CERN HiRadMat facility employed the Super Proton Synchrotron accelerator (SPS) 440 GeV/c proton beam to impact different low-density carbon-based materials targets to assess their performance to these higher energy beam conditions. The study focused on advanced grades of graphitic materials, including isostatic graphite, carbon-fiber reinforced carbon and carbon-SiC materials in addition to flexible expanded graphite. Some of them specifically tailored in collaboration with industry to very specific properties. The objectives of this experiment are: (i) to assess the performance of existing and potentially suitable advanced materials for the currently operating LHC beam dumps and (ii) to study alternative materials for the HL-LHC main dump or for the Future Circular Collider dump systems. The contribution will detail the R&D phase during design, the execution of the experiment, the pre-irradiation tests as well as the first post irradiation examination of the target materials. Lessons learnt and impact on operational devices will also be drawn.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK049  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 04 July 2022
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THPOTK050 CFD Studies of the Convective Heat Transfer Coefficients and Pressure Drops in Geometries Applied to Water Cooling Channels of the Crotch Absorbers of ALBA Synchrotron Light Source 2887
SUSPMF123   use link to see paper's listing under its alternate paper code  
 
  • S. Grozavu, G.A. Raush
    ESEIAAT, Terrassa, Spain
  • J.J. Casas, C. Colldelram, M. Quispepresenter
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  Currently, the storage ring vacuum chambers of ALBA are protected by 156 crotch absorbers made of copper and Glidcop. After more than 10 years of operation as a third-generation light source, the ALBA II project arose, aiming to transform this infrastructure into a fourth-generation synchrotron. This introduces new challenges in terms of the thermal and mechanical design of the future absorbers. The absorbers’ cooling channels consist of a set of 8-mm-diameter holes parallel to each other and drilled into the body of the absorbers. In each hole, there is a 6x1 mm stainless steel concentric inner tube coiled in spiral wires, whose aim is to enhance the heat transfer. The convective heat transfer coefficients used for the original design of the absorbers come from experimental correlations from the literature, and are applied as a global value for the whole system. In this work, Heat Transfer-Computational Fluid Dynamics (HT-CFD) studies of the convective heat transfer coefficients and pressure gradients in three different cooling channel geometries are carried out, aiming at leading the way of designing the cooling systems toward the CFD simulations rather than applying global experimental values. This information will be useful for the sizing of the new absorbers for the ALBA II project.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK050  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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THPOTK051 Corrosion of Copper Components in the Deionized Water Cooling System of ALBA Synchrotron Light Source: Current Research Status and Challenges 2891
 
  • M. Quispe, E. Ayas, J.J. Casas, C. Colldelram, Ll. Fuentes, J. Iglesias
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • A. Garcia
    La Romanica, Barberà del Vallès, Sabadell, Spain
 
  Currently, the ALBA Synchrotron Light Source is carrying out studies on corrosion in copper components of the deionized water cooling circuit. The preliminary studies, based on Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and X-Ray Diffraction (XRD) have shown the presence of intergranular, pitting, and generalized corrosion in the analyzed copper samples. The purpose of this paper is to present new advances in the field of this research, such as: the study of the influence of low velocity water flow in the cooling circuit on the current high dissolved oxygen content (> 6500 ppb), the results of corrosion products found in the cooling circuit, the description of the improper operation of the cooling circuit as a closed loop, and FEA studies of copper components in order to redefine the water flow velocity design criteria to values lower than 3 m/s and thus minimize corrosion by erosion. Finally, in order to attenuate the corrosion rate, preventive solutions are presented such as the viability to install an oxygen content degassing plant, new instrumentation for water quality monitorization, and installation of degassing equipment at strategic positions of the cooling circuit.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK051  
About • Received ※ 07 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 17 June 2022  
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THPOTK052 Muon Collider Graphite Target Studies and Demonstrator Layout Possibilities at CERN 2895
 
  • F.J. Saura Esteban, M. Calviani, D. Calzolari, R. Franqueira Ximenes, A.M. Krainerpresenter, A. Lechner, R. Losito, D. Schulte
    CERN, Meyrin, Switzerland
  • C.T. Rogers
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  Muon colliders offer enormous potential for research of the particle physics frontier. Leptons can be accelerated without suffering large synchrotron radiation losses. The International Muon Collider Collaboration is considering 3 and 10 TeV (CM) machines for a conceptual stage. In the core of the Muon Collider facility lays a MW class production target, which will absorb a high power (1 and 3 MW) proton beam to produce muons via pion decay. The target must withstand high dynamic thermal loads induced by 2 ns pulses at 5-50 Hz. Also, operational reliability must be guaranteed to reduce target exchanges to a minimum. Several technologies for these systems are being studied in different laboratories. We present in this paper the results of a preliminary feasibility study of a graphite-based target, and the different layouts under study for a demonstrator target complex at CERN. Synergies with advanced nuclear systems are being explored for the development of a liquid metal target.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK052  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 18 June 2022
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THPOTK053 Foiled Again: Solid-State Sample Delivery for High Repetition Rate XFELs 2899
 
  • N. Majernik, N. Inzunza, P. Manwanipresenter, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • R.B. Agustsson, A. Moro
    RadiaBeam, Santa Monica, California, USA
  • R. Ash, N.B. Welke
    UW-Madison/PD, Madison, Wisconsin, USA
  • U. Bergmann, A. Halavanau, C. Pellegrini
    SLAC, Menlo Park, California, USA
 
  Funding: Department of Energy DE-SC0009914 and DE-AC02-76SF00515
XFELs today are capable of delivering high intensity pulse trains of x-rays with up-to MHz to sub-GHz frequency. These x-rays, when focused, can ablate a sample in a single shot, requiring the sample material to be replaced in time for the next shot. For some applications, especially serial crystallography, the sample may be renewed as a dilute solution in a high speed jet. Here, we describe the development and characterization of a system to deliver solid state sample material to an XFEL nanofocus. The first application of this system will be an x-ray laser oscillator operating at the copper Kα line with a ~30 ns cavity.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK053  
About • Received ※ 06 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 02 July 2022
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THPOTK054 Proposal of a VHEE Linac for FLASH Radiotherapy 2903
SUSPMF120   use link to see paper's listing under its alternate paper code  
 
  • L. Giuliano, F. Bosco, M. Carillo, D. De Arcangelis, A. De Gregorio, L. Ficcadenti, D. Francescone, G. Franciosini, M. Migliorati, A. Mostacci, L. Palumbo, V. Patera, A. Sarti
    Sapienza University of Rome, Rome, Italy
  • D. Alesini, A. Gallo, A. Vannozzi
    INFN/LNF, Frascati, Italy
  • M. Behtouei, L. Faillace, B. Spataro
    LNF-INFN, Frascati, Italy
  • M.G. Bisogni, F. Di Martino, J.H. Pensavalle
    INFN-Pisa, Pisa, Italy
  • G.A.P. Cirrone, G. Cuttone, G. Torrisi
    INFN/LNS, Catania, Italy
  • V. Favaudon, A. Patriarca
    Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France
  • S. Heinrich
    Institut Curie, Centre de Recherche, Orsay, France
 
  Translation of electron FLASH radiotherapy in clinical practice requires the use of high energy accelerators to treat deep tumours and Very High Electron Energy (VHEE) could represent a valid technique to achieve this goal. In this sce- nario, a VHEE FLASH linac is under study at the University La Sapienza of Rome (Italy) in collaboration with the Italian Institute for Nuclear Research (INFN) and the Curie Insti- tute (France). Here we present the preliminary results of a compact C-band system aiming to reach an high accelerating gradient and an high pulse current necessary to deliver high dose per pulse and ultra-high dose rate required for FLASH effect. We propose a system composed of a low energy high current injector linac followed by a modular section of high accelerating gradient structures. CST code is used to define the required LINAC’s RF parameters and beam dynamics simulations are performed using T-Step, ASTRA and GPT tracking codes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK054  
About • Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
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THPOTK057 ESS RFQ Experimental Modal Analysis 2907
 
  • E. Trachanas, A. Bignami, N. Gazis, B. Jones
    ESS, Lund, Sweden
 
  The European Spallation Source-ESS, which is currently under construction and commissioning at Lund, Sweden is a neutron source that consists of a 2 GeV linear accelerator (LINAC) accelerating a proton beam to a solid Tungsten (W) target. The proton beam is produced by the Ion Source (ISRC) and transported through the Low Energy Beam Transport (LEBT) to the Radio Frequency Quadrupole (RFQ) that will then focus, bunch and accelerate it to 3.6 MeV. The RFQ beam commissioning started in October 2021, following the RF conditioning phase in summer 2021. This current work presents an experimental modal analysis performed on RFQ including the comparative analysis with the modal finite element simulation using the ANSYS software suite. Measurements were performed using accelerometer sensors connected to a data acquisition system excited with an impact hammer. Geophones were used in parallel to the modal measurements in order to monitor the seismic background of the accelerator tunnel. Acquired data were post-processed and analysed with dedicated software, juxtaposed with simulated results in order to determine the resonance frequencies, structural deformation patterns (mode shapes) and error margin between experimental and simulated results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK057  
About • Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOTK058 CERN’s East Experimental Area: A New Modern Physics Facility 2911
 
  • S. Evrard, D. Banerjee, J. Bernhard, F. Carvalho, S. Danzecapresenter, M. Lazzaroni, B. Rae, G. Romagnoli
    CERN, Meyrin, Switzerland
 
  CERN’s East Area has hosted a variety of fixed-target experiments since the 1950s, using four beamlines from the Proton Synchrotron (PS). Over the past 4 years, the experimental area - CERN’s second largest - has undergone a complete makeover. New instrumentation and beamline configuration have improved the precision of data collection, and new magnets and power convertors have drastically reduced the area’s energy consumption. This article will summarize the major challenges encountered for the design of the renovated beamlines and for the preparation and test of the components. The infrastructure was carefully fitted resulting in a very smooth beam commissioning, the details of which will also be presented along with the restart of physics in the second half of 2021. With the return of the beams in the accelerator complex, the East Area’s experiments have taken physics measurements again and the facility’s central role in the modern physics landscape has been restored.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK058  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 05 July 2022
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THPOTK059 Laser System for SuperKEKB RF Gun in Phase III Commissioning 2914
 
  • R. Zhang, M. Yoshida, X. Zhou
    KEK, Ibaraki, Japan
  • H.K. Kumano, N. Toyotomi
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
 
  In order to generate high quality electron beam with high charge in Phase III commissioning of SuperKEKB, some improvements have been done in Ytterbium doped fiber and Neodymium doped YAG (Nd:YAG) hybrid laser system. Spatial reshaping part for the 4th harmonic laser beam at 266 nm has been adopted to realize low emittance electron beam. In addition, for achieving continuous and stable laser operation, position feedback system has also been used to improve the pointing stability of laser beam. In 2021 commissioning of SuperKEKB, stable 2 nC electron beam is generated for high energy ring (HER) injection. Meanwhile, we achieved the best emittance results at B-sector of linac injector and BT line for comparable low injection background and higher injection efficiency. With the aim of generating higher charge electron beam with good quality in the following commissioning, a perspective towards the next step update for current laser system is also introduced.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK059  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 04 July 2022
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THPOTK061 Machine Learning Approach to Temporal Pulse Shaping for the Photoinjector Laser at CLARA 2917
 
  • A.E. Pollard, D.J. Dunning, W.A. Okell, E.W. Snedden
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  The temporal profile of the electron bunch is of critical importance in accelerator areas such as free-electron lasers and novel acceleration. In FELs, it strongly influences factors including efficiency and the profile of the photon pulse generated for user experiments, while in novel acceleration techniques it contributes to enhanced interaction of the witness beam with the driving electric field. Work is in progress at the CLARA facility at Daresbury Laboratory on temporal shaping of the ultraviolet photoinjector laser, using a fused-silica acousto-optic modulator. Generating a user-defined (programmable) time-domain target profile requires finding the corresponding spectral phase configuration of the shaper; this is a non-trivial problem for complex pulse shapes. Physically informed machine learning models have shown great promise in learning complex relationships in physical systems, and so we apply machine learning techniques here to learn the relationships between the spectral phase and the target temporal intensity profiles. Our machine learning model extends the range of available photoinjector laser pulse shapes by allowing users to achieve physically realisable configurations for arbitrary temporal pulse shapes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK061  
About • Received ※ 30 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 03 July 2022
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THPOTK062 Thermal Modeling and Benchmarking of Crystalline Laser Amplifiers 2921
 
  • D.T. Abell, D.L. Bruhwilerpresenter, P. Moeller, R. Nagler, B. Nash, I.V. Pogorelov
    RadiaSoft LLC, Boulder, Colorado, USA
  • Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
    LBNL, Berkeley, USA
  • N.B. Goldring
    STATE33 Inc., Portland, Oregon, USA
 
  Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
Ti:sapphire crystals constitute the lasing medium of a class of lasers valued for their wide tunability and ultra-short, ultra-high intensity pulses. When operated at high power and high repetition rate (1kHz), such lasers experience multiple effects that can degrade performance. In particular, thermal gradients induce a spatial variation in the index of refraction, hence thermal lensing*. Using the open-source finite-element code FEniCS***, we solve the relevant partial differential equations to obtain a quantitative measure of the disruptive effects of thermal gradients on beam quality. We present thermal simulations of a pump laser illuminating a Ti:sapphire crystal. From these simulations we identify the radial variation in the refractive index, and hence the extent of thermal lensing. In addition, we present analytic models used to estimate the effect of thermal gradients on beam quality. This work generalizes to other types of crystal amplifiers.
* S. Cho, et al., Appl. Phys. Express, 11:092701, 2018.
** M. Born & E. Wolf, Principles of Optics, Cambridge Univ. Press, 1980.
*** The FEniCS computing platform, https://fenicsproject.org
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK062  
About • Received ※ 13 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOTK063 Open Source Software to Simulate Ti:Sapphire Amplifiers 2925
 
  • D.L. Bruhwiler, D.T. Abell, B. Nash
    RadiaSoft LLC, Boulder, Colorado, USA
  • Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
    LBNL, Berkeley, USA
  • N.B. Goldring
    STATE33 Inc., Portland, Oregon, USA
 
  Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
The design of next-generation PW-scale fs laser systems, including scaling to kHz rates and development of new laser gain media for efficiency, will require parallel multiphysics simulations with realistic errors and nonlinear optimization. There is currently a lack of broadly available modeling software that self-consistently captures the required physics of gain, thermal loading and lensing, spectral shaping, and other effects required to quantitatively design such lasers.* We present initial work towards an integrated multiphysics capability for modeling pulse amplification in Ti:Sa lasers. All components of the software suite are open source. The Synchrotron Radiation Workshop (SRW)** is being used for physical optics, together with Python utilities. The simulations are being validated against experiments.
* R. Falcone et al., Brightest Light Initiative Workshop Report (2019).
** https://github.com/ochubar/srw
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK063  
About • Received ※ 14 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
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