Author: Honda, Y.
Paper Title Page
MOPO082 Commissioning Status of the Linac for the iBNCT Project 174
 
  • M. Sato, Z. Fang, M.K. Fukuda, Y. Fukui, K. Futatsukawa, Y. Honda, K. Ikegami, H. Kobayashi, C. Kubota, T. Kurihara, T. Miura, T. Miyajima, F. Naito, K. Nanmo, T. Obina, T. Shibata, T. Sugimura, A. Takagi, E. Takasaki
    KEK, Ibaraki, Japan
  • K. Hasegawa
    JAEA, Ibaraki-ken, Japan
  • H. Kumada, Y. Matsumoto, Su. Tanaka
    Tsukuba University, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan
  • N. Nagura, T. Ohba
    Nippon Advanced Technology Co., Ltd., Tokai, Japan
  • T. Onishi
    Tsukuba University, Ibaraki, Japan
  • T. Ouchi, H. Sakurayama
    ATOX, Ibaraki, Japan
 
  Boron neu­tron cap­ture ther­apy (BNCT) is one of the par­ti­cle-beam ther­a­pies which use sec­ondary prod­ucts from a neu­tron cap­ture on boron medica­ments im­planted into can­cer cells. This has been orig­i­nally stud­ied with neu­trons from nu­clear re­ac­tors, mean­while, many ac­tiv­i­ties have been re­cently pro­jected with ac­cel­er­a­tor-based neu­tron gen­er­a­tion. In the iBNCT (Ibaraki BNCT) pro­ject, the ac­cel­er­a­tor is con­sisted with a radio fre­quency quadru­pole (RFQ) and an Al­varez type drift-tube linac (DTL). Pro­tons ex­tracted from an ion source are ac­cel­er­ated up to 3 MeV and 8 MeV, re­spec­tively, and bom­barded onto a beryl­lium tar­get to gen­er­ate neu­trons. The de­sign of the linac is based on the J-PARC one, but the most sig­nif­i­cant dif­fer­ence is the higher duty fac­tor to have a suf­fi­cient ep­ither­mal neu­tron flux for BNCT. We have started the com­mis­sion­ing from the end of 2016, and the beam cur­rent of 1.3 mA with a rep­e­ti­tion of 50 Hz has been achieved with an ac­cept­able sta­bil­ity. Fur­ther beam com­mis­sion­ing and re­in­force­ment of the vac­uum and cool­ing water sys­tem will be per­formed to­ward higher beam cur­rent. In this con­tri­bu­tion, the cur­rent sta­tus and fu­ture prospects of the linac will be pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO082  
About • paper received ※ 12 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TU1P03
Observation of Resonant Coherent Diffraction Radiation from a Multi-bunch Electron Beam Passing Through an Optical Cavity  
 
  • Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, T. Uchiyama, N. Yamamoto
    KEK, Ibaraki, Japan
  • T. Hotei
    Sokendai, Ibaraki, Japan
 
  Funding: This work was supported by JSPS KAKENHI Grant Number 16H05991.
En­ergy Re­cov­ery Linac can re­al­ize a linac-type beam at a high cur­rent. An ERL test ac­cel­er­a­tor, cERL, has been con­structed in KEK. Uti­liz­ing these fea­tures of the ERL beam, low emit­tance, short bunch, and high rep­e­ti­tion rate, we have been de­vel­op­ing a unique ter­a­hertz ra­di­a­tion source of res­o­nant co­her­ent dif­frac­tion ra­di­a­tion. An op­ti­cal res­o­nant cav­ity con­sists of two con­cave mir­rors with a beam hole at the cen­ter was in­stalled in the re­turn-loop of cERL. When the multi-bunch elec­tron beam passes through the cav­ity, it ra­di­ates co­her­ent dif­frac­tion ra­di­a­tion in the cav­ity. If the round-trip time of the cav­ity pre­cisely matches the beam rep­e­ti­tion, the ra­di­a­tion of the bunches are stacked co­her­ently and stim­u­lates the en­ergy con­ver­sion process from the beam to the ra­di­a­tion. Mea­sur­ing the ter­a­hertz ra­di­a­tion power while scan­ning the cav­ity length, we ob­served a sharp res­o­nance peak show­ing the re­al­iza­tion of the stim­u­lated emis­sion. The cav­ity was care­fully de­signed to tune the car­rier-en­ve­lope-off­set to be zero. It al­lows to ex­cite wide-band lon­gi­tu­di­nal modes si­mul­ta­ne­ously, and re­al­ize a mode-locked ter­a­hertz pulse.
 
slides icon Slides TU1P03 [1.740 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPO074 Design and Fabrication of KEK Superconducting RF Gun #2 510
 
  • T. Konomi, Y. Honda, E. Kako, Y. Kobayashi, S. Michizono, T. Miyajima, H. Sakai, K. Umemori, S. Yamaguchi, M. Yamamoto
    KEK, Ibaraki, Japan
 
  Su­per­con­duct­ing RF gun can re­al­ize high ac­cel­er­a­tion volt­age and high beam rep­e­ti­tion. KEK has been de­vel­op­ing the 1.3 GHz el­lip­ti­cal type 1.5 cell su­per­con­duct­ing RF gun to in­ves­ti­gate fun­da­men­tal per­for­mance. A sur­face clean­ing method and tools are de­vel­oped by using KEK SR­F­GUN #1 and high sur­face peak gra­di­ent 75 MV/m was achieved with­out field emis­sion. SR­F­GUN #2 which equips the he­lium jacket and can be op­er­ated with elec­tron beam was de­signed based on the SR­F­GUN #1. It can be op­er­ated with trans­mit type pho­to­cath­ode which in­clude su­per­con­duct­ing trans­par­ent ma­te­r­ial. The cath­ode plug is cooled by ther­mal con­duct­ing from the 2 K he­lium jacket and pho­to­cath­ode will be kept around 2K to main­tain su­per­con­duc­tiv­ity. Bulk nio­bium pho­to­cath­ode plug and sub­strate will used for the fun­da­men­tal per­for­mance test. In par­al­lel, the pho­to­cath­ode de­po­si­tion cham­ber for multi-al­kali pho­to­cath­ode will be pre­pared.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO074  
About • paper received ※ 12 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)