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Kawamata, H.

Paper Title Page
MOPD044 Fabrication of the New RFQ for the J-PARC Linac 783
 
  • T. Morishita, K. Hasegawa, Y. Kondo
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Baba, Y. Hori, H. Kawamata, H. Matsumoto, F. Naito, Y. Saito, M. Yoshioka
    KEK, Ibaraki
  
 

The J-PARC RFQ (length 3.1m, 4-vane type, 324 MHz) ac­cel­er­ates a neg­a­tive hy­dro­gen beam from 0.05MeV to 3MeV to­ward the fol­low­ing DTL. As the trip rates of the prac­ti­cal­ly using RFQ in­creased in au­tumn 2008, we start­ed the prepa­ra­tion of a new RFQ as a back­up ma­chine. The beam dy­nam­ics de­sign of the new RFQ is the same as the cur­rent cav­i­ty, how­ev­er, the en­gi­neer­ing and RF de­signs are changed. The pro­cess­es of the vane ma­chin­ing and the sur­face treat­ments have been care­ful­ly con­sid­ered to re­duce the dis­charge prob­lem. The vac­u­um braz­ing tech­nique has been cho­sen for vane in­te­gra­tion. In this re­port, the de­tailed de­sign will be de­scribed with the progress of the fab­ri­ca­tion of the new RFQ.

  
MOPEC039 Developments for Beam Intensity Increase and Beam Quality Improvement in the RCNP Cyclotrons 546
 
  • M. Fukuda, K. Hatanaka, H. Kawamata, M. Kibayashi, T. Saito, H. Tamura, T. Yorita
    RCNP, Osaka
  
 

An up­grade pro­gram of the RCNP cy­clotron fa­cil­i­ty for in­crease of beam in­ten­si­ty and im­prove­ment of beam qual­i­ty is in progress to meet re­quire­ments from re­search in nu­cle­ar physics and in­dus­tri­al ap­pli­ca­tions using sec­on­dar­i­ly pro­duced par­ti­cles such as neu­trons, muons and ra­dioiso­topes. A 2.45 GHz ECR ion source using a set of per­ma­nent mag­nets was de­vel­oped for high in­ten­si­ty pro­ton beam pro­duc­tion. The pro­ton beam in­ten­si­ty more than 0.5 mA at an ex­trac­tion en­er­gy of 15 keV has been ob­tained with a pro­ton ratio more than 80 %. The qual­i­ty of the pre-ac­cel­er­at­ed beam from the K140 in­jec­tor AVF cy­clotron has been im­proved by a flat-top(FT) ac­cel­er­a­tion sys­tem to en­hance the beam trans­mis­sion to the K400 ring cy­clotron. Transver­sal res­o­nant mode of a dee elec­trode with a span angle of 180 de­grees was in­ves­ti­gat­ed to achieve the FT ac­cel­er­a­tion in the fre­quen­cy re­gion from 50 to 60 MHz. In this paper, de­vel­op­ments for high in­ten­si­ty pro­ton beam ac­cel­er­a­tion and beam qual­i­ty im­prove­ment using the FT ac­cel­er­a­tion sys­tem of the AVF cy­clotron will be main­ly pre­sent­ed.