TU1A —  Plenary Session 4   (18-Sep-18   08:30—10:30)
Chair: S. Fu, IHEP, Beijing, People’s Republic of China
Paper Title Page
TU1A01 Challenges in Superconducting Accelerating Module Design and Construction for High Power Proton Accelerators 280
 
  • C. Madec
    CEA/DSM/IRFU, France
 
  CEA is engaged in the construction of the IFMIF, SARAF and ESS superconducting linacs and in particular in the design and production of a their accelerating cryomodules: 1 low-beta half-wave 176 MHz resonators for IFMIF, 4 low-beta half-wave 176 MHz resonators for SARAF and 30 medium and high-beta elliptical cavity resonators for ESS. The developments of these RF cryomodules, although at various stages, are led in parallel by the cryomodule team at CEA-Saclay, including all RF, mechanical, thermal, cryogenic, integration and QA-QC aspects in a global approach which attempts to optimise synergies and lessons learnt between these projects. A status report will be presented describing the common approaches and methods, and the systemic particularities of each project.  
slides icon Slides TU1A01 [11.896 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TU1A01  
About • paper received ※ 14 September 2018      issue date ※ 18 January 2019  
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TU1A02
Development of Normal-conducting High-gradient Accelerating Structures  
 
  • J. Shi
    TUB, Beijing, People’s Republic of China
 
  X-band high-gradient accelerating structures operating at the gradient of 80-100MV/m are proposed for different applications including compact linear collider and compact X-ray facilities. A traveling-wave structure as well as single-cell test structures with choke-mode damping feature were developed in Tsinghua University and high-power tested. A prototype structure with CLIC-based design, namely T24-THU#1, has reached 110 MV/m and several choke-mode single-cell structures reached 130MV/m during test. The high-gradient technique will be applied to Tsinghua Thomson-scattering X-ray source with two new developed 0.6m-long structures for 80MV/m acceleration.  
slides icon Slides TU1A02 [10.927 MB]  
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TU1A03 Status and Issues (Microphonics, LFD, MPS) with TRIUMF ARIEL e-Linac Commissioning 286
 
  • S.R. Koscielniak, M. Alcorta, F. Ames, E. Chapman, K. Fong, B. Humphries, O.K. Kester, D. Kishi, R.E. Laxdal, Y. Ma, T. Planche, M. Rowe, S.D. Rädel, V.A. Verzilov, Z.Y. Yao
    TRIUMF, Vancouver, Canada
 
  The ARIEL electron linac (e-linac) is designed to generate cw beams of up to 30 MeV and 10 mA for delivery to a photo-convertor. Bremsstrahlung induced fission of a production target yields neutron-rich rare isotope beams to be supplied to the ISAC experimental facilities. The beam power will eventually reach 300 kW, and a machine protection system (MPS) with 10 μs rapidity is essential. The e-linac, which adopts 1.3 GHz, 2K SRF technology, is composed of a 10 MeV single-cavity injector cryomodule (EINJ) and a 20 MeV two-cavity accelerator cryomodule (EACA). The latter has vector-sum control of two cavities driven from a single klystron. Beam commissioning of these systems is ongoing since 2016. The magnetic optics and MPS commissioning to 10 MeV is reported herein. Beam has been accelerated up to 25 MeV, and thread-ed to the high energy dump (EHD). A campaign to investigate microphonics driving terms, LN2 disturb-ances, and a ponderomotive instability in the EACA, is underway.  
slides icon Slides TU1A03 [9.683 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TU1A03  
About • paper received ※ 17 September 2018      issue date ※ 18 January 2019  
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TU1A04
FRIB Cavities and Cryomodule Production  
 
  • C. Compton
    FRIB, East Lansing, Michigan, USA
 
  FRIB is producing 49 cryomodules (CMs) with six types (four types of accelerating CMs and two types of matching CMs). Four types of SRF cavities are installed; β = 0.041 Quarter Wave Resonator (QWR), β = 0.085 QWR, β = 0.29 Half Wave Resonator (HWR), and β = 0.53 HWR. The superconducting focusing solenoids and diagnostics are installed in the CMs. By the end of October, 2017, 13 CMs were integrated tested and have been placed at the FRIB tunnel. In addition, 3 CMs were assembled, and 7 cold masses were completed. The remaining 26 CMs production is on track. Challenges overcome during the course of CMs development and production were presented with the updated status.  
slides icon Slides TU1A04 [13.283 MB]  
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TU1A05 Seamless Quarter Wave Resonators for HIE ISOLDE 292
 
  • W. Venturini Delsolaro, A. Miyazaki
    CERN, Geneva, Switzerland
 
  The HIE-ISOLDE post accelerator consists of 4 cryomodules with 5 niobium-coated Quarter Wave Reso-nators (QWR) each. The standard manufacturing tech-nique was to machine the inner and outer conductor sepa-rately, to shrink-fit the 2 pieces and to apply an electron beam welding at the interface. Due toμcracks, ob-served on some of the cavities around the welds, we took the decision to explore the possibility of a seamless de-sign. First cavities became available in late 2017 and were then cold-tested in the vertical cryostat. These seam-less coated quarter wave resonators have shown some of the highest Q-values of all HIE-ISOLDE cavities in the acceptance tests. Furthermore, we studied the cavity per-formance with different compensations of the earth mag-netic field and different temperature gradients upon cool down. These tests have demonstrated record-breaking RF surface fields for the Nb/Cu technology. This paper re-views the design and fabrication and reports on the cold tests results of seamless quarter wave resonators, and of possible future applications  
slides icon Slides TU1A05 [30.518 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TU1A05  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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