Author: Maurice, L.
Paper Title Page
THPOGE23 Vertical Electro-Polishing of 704 MHz Resonators Using Ninja Cathode: Gradients Over 40 MV/m Achieved on ESS Single-Cell Cavity 844
THOPA08   use link to see paper's listing under its alternate paper code  
 
  • F. Éozénou, M. Baudrier, E. Cenni, E. Fayette, L. Maurice, C. Servouin
    CEA-DRF-IRFU, France
  • H. Hayano, H. Ito, S. Kato, T. Kubo, H. Monjushiro, T. Saeki
    KEK, Ibaraki, Japan
  • Y.I. Ida, K. Nii, T.Y. Yamaguchi
    MGH, Hyogo-ken, Japan
  • G. Jullien
    CEA-IRFU, Gif-sur-Yvette, France
  
  CEA, KEK and Marui Galvanizing Company have been collaborating to apply the Vertical Electropolishing (VEP) process of elliptical SRF cavities to a 704MHz single-cell ESS-type cavity, using a rotating so called and patented "Ninja" cathode. First presented results* were promising with a gradient of 27MV/m achieved, without any heat treatment applied. The performance has been pushed further since. The cavity has undergone a heat treatment at 650°C during 10h, followed by a final VEP sequence and a baking at 120°C during 48h hours. The achieved gradient at 2K was 44MV/m (power limitation), and the quality factor Q0 exceeding 5·1010 up to 10 MV/m. The superiority of VEP compared to standard "BCP" chemical treatment is demonstrated and we intend now to scale the process to 5-Cell β=0.86 ESS cavity. We also intend to push further the performance by applying "2-step baking" (75°C and 120°C) proposed by FNAL, which was successfully applied at CEA Saclay on 1300MHz single-cell resonators with gradients above 50MV/m achieved after VEP bulk treatment.
* TUPCAV001, SRF 2021 		 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOGE23  
About • Received ※ 24 August 2022 — Revised ※ 01 September 2022 — Accepted ※ 09 September 2022 — Issue date ※ 16 September 2022
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THPOGE01 Study on the Multipactor Barriers of the SARAF-Phase 2 Low-Beta and High-Beta Superconducting Cavities 802
 
  • G. Ferrand, L. Maurice
    CEA-IRFU, Gif-sur-Yvette, France
  • M. Baudrier, N. Pichoff
    CEA-DRF-IRFU, France
  
  CEA is committed to delivering a Medium Energy Beam Transfer line and a superconducting linac (SCL) for SARAF accelerator in order to accelerate 5 mA beam of either protons from 1.3 MeV to 35 MeV or deuterons from 2.6 MeV to 40 MeV. The SCL contains 13 half-wave resonator (HWR) low beta cavities (β= 0.09) at 176 MHz and 14 HWR high-beta cavities (β = 0.18) at 176 MHz. The low-beta and high-beta series were qualified in 2021 and 2022 respectively. This contribution will focus on the observation of the multipactor barriers for all cavi-ties. It will present series of data obtained during the conditioning of these cavities  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOGE01  
About • Received ※ 27 July 2022 — Revised ※ 23 August 2022 — Accepted ※ 07 September 2022 — Issue date ※ 15 September 2022
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