TUO2AB —  Working Group F   (11-Nov-14   10:50—12:30)
Chair: T. Toyama, KEK, Ibaraki, Japan
Paper Title Page
TUO2AB01
 Beam Instrumentation and Limitations for Multi MW Pulsed Proton Linacs  
 
  • A. Jansson
    ESS, Lund, Sweden
  
  This pre­sen­ta­tion fo­cuses on the chal­lenges and lim­i­ta­tions re­lated to mea­sur­ing some of the rel­e­vant prop­er­ties of very high in­ten­sity pulsed pro­ton beams in lin­ear ac­cel­er­a­tors. Among such prop­er­ties are the trans­verse and lon­gi­tu­di­nal dis­tri­b­u­tions, in­clud­ing the tails (halo). Chal­lenges in­clude en­ergy de­po­si­tion in in­va­sive de­vices, as well as as very short bunches in com­bi­na­tion with slow (beta<1) beams. An overview of meth­ods used or cur­rently con­sid­ered will be given.  
slides icon Slides TUO2AB01 [7.484 MB]  
 
TUO2AB02
 Halo Matching for High Intensity Linacs and Dedicated Diagnostics  
 
  • N. Chauvin, J. Marroncle, P.A.P. Nghiem
    CEA/DSM/IRFU, France
  • P. Abbon, D. Uriot
    CEA/IRFU, Gif-sur-Yvette, France
  
  Min­i­miz­ing beam losses is one of the biggest chal­lenge of very high power linac (MW range). In some cases, beam match­ing con­cen­trat­ing on min­i­miz­ing emit­tance growth is not the most ap­pro­pri­ate ap­proach; a di­rect match­ing of the halo it­self is prefer­able. We pro­pose a method con­sist­ing in min­i­miz­ing the beam ex­tent, using the Par­ti­cle Swarm Op­ti­miza­tion al­go­rithm that is well suit­able to non­lin­ear sys­tems gov­erned by many pa­ra­me­ters. In this ar­ti­cle, an ap­pli­ca­tion of halo match­ing sim­u­la­tions is given in the case of the IFMIF su­per­con­duct­ing linac. De­vel­op­ment of ded­i­cated di­ag­nos­tics for in-situ im­ple­men­ta­tion of this method on linacs are briefly pre­sented. The beam di­ag­nos­tic types and lo­ca­tions needed for ma­chine tun­ing with halo match­ing are de­tailed.  
slides icon Slides TUO2AB02 [7.922 MB]  
 
TUO2AB03 Beam Diagnostics for the Detection and Understanding of Beam Halo 183
 
  • K. Wittenburg
    DESY, Hamburg, Germany
  
  A gen­eral view that has been re­cently reached by dif­fer­ent meth­ods of halo di­ag­nos­tics of high bright­ness hadron beams will be given. The per­for­mance (dy­namic range, ac­cu­racy …) of var­i­ous mon­i­tor types will be com­bined with the de­mands from beam dy­nam­ics of dif­fer­ent ma­chines to dis­cuss which meth­ods can be en­vis­aged for the fu­ture. The dis­cus­sion will in­clude low and high en­ergy ma­chines and their re­lated halo de­tec­tion schemes.  
slides icon Slides TUO2AB03 [3.154 MB]  
 
TUO2AB04 Two-Dimensional and Wide Dynamic Range Profile Monitor Using OTR / Fluorescence Screens for Diagnosing Beam Halo of Intense Proton Beams 187
 
  • Y. Hashimoto, M. Tejima, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • A. Akino, Y. Omori, S. Otsu, H. Sakai
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  
  An in­stru­ment which can di­ag­nose a two-di­men­sional beam pro­file of the beam core to­gether with the beam halo in wide dy­namic range has been de­vel­oped in the J-PARC. The in­stru­ment con­sists of OTR (Ti foil of 10 μm) screen, flu­o­res­cence (Cr doped alu­mina) screen, an Offner type imag­ing sys­tem, and a cam­era with image in­ten­si­fier. The beam core is ob­served with OTR and the beam halo is ob­served with flu­o­res­cence screen, re­spec­tively. A com­bi­na­tion of ob­ser­va­tions of beam core and halo with these two dif­fer­ent screens that have dif­fer­ent sen­si­tiv­i­ties al­lowed us an ob­ser­va­tion in wide-dy­namic range. The four flu­o­res­cence screens are set in ver­ti­cal and hor­i­zon­tal arrange­ment. Both the OTR and flu­o­res­cence are fo­cused by an Offner type op­tics hav­ing a very wide in­ci­dent pupil makes these im­ages. This in­stru­ment is set in the beam trans­port line be­tween the rapid cy­cling syn­chro­tron and the main ring. A two di­men­sional pro­file of the beam core and the halo were suc­cess­fully ob­served in six order of mag­ni­tude at pro­jected plane using in­tense 3 GeV pro­ton beams of 1.5 x 1013 pro­tons. This mon­i­tor has a big ad­van­tage for the di­ag­nos­tic of beam core and halo shapes in real space.
[1] Y. Hashimoto, et al., A Development of High Sensitive Beam Profile Monitor Using Multi-Screen, Proc. IBIC2013, 338-341. 		 
slides icon Slides TUO2AB04 [3.172 MB]