Author: Tamura, J.
Paper Title Page
MOPOGE13 Acceleration Efficiency of TE-Mode Structures for Proton Linacs 177
 
  • J. Tamura, Y. Kondo, T. Morishita
    JAEA/J-PARC, Tokai-mura, Japan
  • F. Naito, M. Otani
    KEK, Tokai, Ibaraki, Japan
  
  Var­i­ous types of cav­ity struc­tures are typ­i­cally used in hadron linacs, de­pend­ing on the en­ergy range of the beam par­ti­cle. This is es­pe­cially the case in a nor­mal-con­duct­ing linac, be­cause the cav­ity’s ac­cel­er­a­tion ef­fi­ciency varies with the ve­loc­ity of the syn­chro­nous par­ti­cle. For low-en­ergy pro­ton ac­cel­er­a­tion, while Al­varez drift-tube linacs (DTLs) are the most preva­lent, TE-mode ac­cel­er­at­ing struc­tures, which could also be called H-mode struc­tures, are also widely used im­me­di­ately after an ini­tial ra­diofre­quency quadru­pole linac (RFQ). At pre­sent, the rep­re­sen­ta­tive struc­tures of TE modes are in­ter­dig­i­tal H-mode (IH) DTL and cross­bar H-mode (CH) DTL, which are based on the TE11-mode pill­box cav­ity and TE21-mode pill­box cav­ity, re­spec­tively. In this pre­sen­ta­tion, ac­cel­er­a­tion ef­fi­ciency of TE-mode struc­tures in­clud­ing higher-or­der TE-modes such as TE31 and TE41 was com­par­a­tively re­viewed with Al­varez DTL. This study shows that IH-DTL and CH-DTL have a larger shunt im­ped­ance than Al­varez DTL for pro­ton ac­cel­er­a­tion below 10 MeV, and fur­ther­more for the TEm1-mode struc­tures, the ro­ta­tional sym­me­try of the elec­tric field im­proves with in­creas­ing an­gu­lar index m.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE13  
About • Received ※ 30 August 2022 — Revised ※ 06 September 2022 — Accepted ※ 14 September 2022 — Issue date ※ 26 September 2022
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MOPOGE14 Current Status of the Spoke Cavity Prototyping for the JAEA-ADS Linac 180
 
  • J. Tamura, Y. Kondo, F. Maekawa, S.I. Meigo, B. Yee-Rendón
    JAEA/J-PARC, Tokai-mura, Japan
  • T. Dohmae, E. Kako, H. Sakai, K. Umemori
    KEK, Ibaraki, Japan
  
  The Japan Atomic En­ergy Agency (JAEA) has pro­posed an ac­cel­er­a­tor-dri­ven sub­crit­i­cal sys­tem (ADS) to ef­fi­ciently re­duce high-level ra­dioac­tive waste gen­er­ated at nu­clear power plants. One of the chal­leng­ing R&D as­pects of ADS is the re­li­a­bil­ity of the ac­cel­er­a­tor. In prepa­ra­tion for the full-scale de­sign of the CW pro­ton linac for the JAEA-ADS, we are now pro­to­typ­ing a low-beta (around 0.2) sin­gle spoke cav­ity. Since there is no ex­pe­ri­ence in Japan in man­u­fac­tur­ing a su­per­con­duct­ing spoke cav­ity, pro­to­typ­ing and per­for­mance test­ing of the cav­ity is es­sen­tial to en­sure the fea­si­bil­ity of the JAEA-ADS linac. In the Japan­ese fis­cal year 2021, we have started weld­ing cav­ity parts to­gether. By pre­lim­i­nar­ily ex­am­in­ing the elec­tron beam weld­ing con­di­tions, each press-formed nio­bium part was joined with a smooth weld­ing bead. The cur­rent sta­tus of the spoke cav­ity pro­to­typ­ing for the JAEA-ADS linac is pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOGE14  
About • Received ※ 01 August 2022 — Revised ※ 21 August 2022 — Accepted ※ 14 September 2022 — Issue date ※ 26 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)