Vertical Electro-Polishing of 704 MHz Resonators Using Ninja Cathode: Gradients Over 40 MV/m Achieved on ESS Single-Cell Cavity

Autor: Éozénou, Fabien, Baudrier, Matthieu, Cenni, Enrico, Fayette, Elise, Hayano, Hitoshi, Ida, Yoshiaki, Ito, Hayato, Jullien, Grégoire, Kato, Shigeki, Kubo, Takayuki, Maurice, Luc, Monjushiro, Hideaki, Nii, Keisuke, Saeki, Takayuki, Servouin, Christophe, Yamaguchi, Takanori
Přispěvatelé: Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Département de Physique Nucléaire (ex SPhN) (DPHN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: JACoW
31st Linear Accelerator Conference
31st Linear Accelerator Conference, Aug 2022, Liverpool, United Kingdom. pp.844-847, ⟨10.18429/JACoW-LINAC2022-THPOGE23⟩
DOI: 10.18429/JACoW-LINAC2022-THPOGE23⟩
Popis: 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.
Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK
Databáze: OpenAIRE
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