MC7: Accelerator Technology
T13 Cryogenics
Paper Title Page
TUPMP006 Cryogenic Tests of the SPIRAL2 LINAC Systems 1240
 
  • A. Ghribi, P.-E. Bernaudin, R. Ferdinand, A.V. Vassal
    GANIL, Caen, France
 
  Two full cool-down of the SPIRAL2 superconducting LINAC have been performed in 2017 and 2018 respectively, followed by a total of around 5 months of tests at 4 K. Several cool-down strategies were tested, in order to minimize 100 K effect on the SC cavities. Helium bath regulations (level and pressure) have been tested and optimized. Effects of pressure instabilities and coupling with the cryogenic plant have also been observed. Cryogenic performances of each cryomodule have been measured. Low-level RF measurements were also performed on all cavities and showed unidentified modulations at frequencies around 5Hz. These turned out to be thermoacoustic oscillations (TAO) on the cryogenic lines, which generate important pressure instabilities. Several solutions to remove TAO and cure these instabilities have been tested and one has been successfully deployed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP006  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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TUPMP045 The Protection Instrument for Cryogenic Phase Separator Pressure Relief Valve of TPS Beamline 1350
 
  • C.C. Liang, C.Y. Chang, C.F. Chang, Y.H. Guo, M.H. Lee, C.Y.L. Liu, T.-C. Yu
    NSRRC, Hsinchu, Taiwan
 
  TPS (Taiwan Photon Source) beamlines have operated for three years after the successful commission in 2015. Recently, the electromagnetic activated pressure relief valve of cryogenic phase separator of beamline had malfunction due to the rust of its control circuits. After on site observation and temperature records, the water was found to be condensed around the outlet area due to fast temperature dropping near the valve as it was activated. Such situation would cause the rust of metal components due to humidity after a certain period of time. To avoid such event, fan is used to blow the condensed water and silicone heat belts are added to increase the local temperature with unique designed clamp for fixing the fan, sensors and safety circuit breaker. Via the temperature control system, the temperature monitoring, setting and the abnormal situation can be access on web page through Ethernet to make sure the proper operation of the protected devices. The instrument has been operated since Dec. 2018. After four months of operation, the moist situation has been improved and the relief valve is no longer frosted.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP045  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPMP047 Upgrade of the Cryogenic Control System for SRF Modules at the Taiwan Light Source 1356
 
  • F.-T. Chung, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
    NSRRC, Hsinchu, Taiwan
 
  An upgrade of the cryogenic control system for superconducting radio-frequency (SRF) modules of the Taiwan Light Source (TLS) has been completed. The biggest challenge was to recover all protection and operational functions, while minimizing the quantity of vented helium from SRF modules while replacing valve controllers. Gradually, this work was finished within several one- and ten-day scheduled machine shutdown periods for accelerator maintenance. No large helium vent nor pollution of the cryogenic system occurred during all component replacements and function verifications. Functions of the cryogenic electronics were improved, whereas the valve controllers are upgraded to new versions to increase reliability and availability. Communications with the data acquisition system was also secured by buffered signal processing module so that device shutdown of the data acquisition system will not interrupt the cryogenic valve operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP047  
About • paper received ※ 29 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPTS112 Stand-alone Accelerator System Based on SRF Quarter-wave Resonators 2185
 
  • S.V. Kutsaev, R.B. Agustsson, R.D. Berry, D. Chao
    RadiaBeam, Santa Monica, California, USA
  • Z.A. Conway
    ANL, Argonne, Illinois, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy under contracts DE-SC0017101 and DE-AC02-06CH11357. This research used resources of DOE ANL’s ATLAS facility.
Superconducting accelerators are large and complex systems requiring a central refrigerator and distributed transfer systems to supply 2-4 K liquid helium. Stand-alone, cryocooler-based systems are of interest both to scientific facilities and industrial applications, as they do not require large cryogenic infrastructure and trained specialists for operation. Here we present our approach to the challenge of using low-power commercially available cryocoolers to operate niobium superconducting resonators at 4.4 K with high accelerating voltages and several watts of heating. Engineering and design results from RadiaBeam Systems, collaborating with Argonne National Laboratory, for a stand-alone liquid-cooled cryomodule with 10 Watts of 4.4 K cooling capacity housing a 72.75 MHz quarter-wave resonator operating at 2 MV for synchronous ions travelling at 7.7% of speed of light will be discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS112  
About • paper received ※ 30 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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TUPTS114 Electron Stimulated Desorption from Cryogenic NEG-Coated Surfaces 2193
SUSPFO135   use link to see paper's listing under its alternate paper code  
 
  • R. Sirvinskaite, M.D. Cropper
    Loughborough University, Loughborough, Leicestershire, United Kingdom
  • A.N. Hannah, O.B. Malyshev, R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • S. Wang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  Non-Evaporable Getter (NEG) coating has been used for years in many particle accelerators due to its advantages like evenly distributed pumping speed, low thermal outgassing, and low photon, electron and ion stimulated desorption yields. Although NEG coating has been tested at room temperatures intensively, there is little data on its behaviour at cryogenic temperatures. Tests in this environment are important for the Future Circular Collider (FCC) study and other accelerator facilities where the operational conditions of the beam screen are restricted to cryogenic temperatures. This work will provide some preliminary results on NEG properties at low temperatures, e.g. pumping speed and capacity, as well as its behaviour under electron bombardment, where electron stimulated desorption (ESD) yields will be calculated. The ternary Ti-Zr-V coating, deposited with dense and columnar structure, will be the first material to be tested at cryogenic temperatures in ASTeC Daresbury laboratory. The results were compared with the ones obtained at room temperature, offering an insight into the behaviour of NEG-coated cryogenic chambers when beam-induced effects are present.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS114  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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