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Peters, C.C.

Paper Title Page
MOPE101 Parasitic Profile Measurement of 1 MW Neutron Production Beam at SNS Superconducting Linac 1221
 
  • Y. Liu, A.V. Aleksandrov, C.D. Long
    ORNL, Oak Ridge, Tennessee
  • C.C. Peters
    ORNL RAD, Oak Ridge, Tennessee
  
 

A laser wire sys­tem* has been de­vel­oped in the Spal­la­tion Neu­tron Source (SNS) su­per­con­duct­ing linac (SCL). The SNS laser wire sys­tem is the world largest of its kind with a ca­pa­bil­i­ty of mea­sur­ing pro­files of an op­er­a­tional hy­dro­gen ion (H-) beam at each of the 23 cry­omod­ule sta­tions along the SCL by using a sin­gle light source. Present­ly 9 laser wire sta­tions have been com­mis­sioned that mea­sure pro­files of the H- beam at en­er­gy lev­els from 200 MeV to 1 GeV. The laser wire di­ag­nos­tics has no mov­ing parts in­side the beam pipe and can be run par­a­sit­i­cal­ly on a neu­tron pro­duc­tion H- beam. This talk re­ports our re­cent study of the laser wire pro­file mea­sure­ment per­for­mance. Par­a­sitic pro­file mea­sure­ments have been con­duct­ed at mul­ti­ple lo­ca­tions of SCL on an op­er­a­tional one-megawatt neu­tron pro­duc­tion beam that SNS re­cent­ly achieved as a new world record. We will de­scribe ex­per­i­men­tal in­ves­ti­ga­tions of the laser wire sys­tem per­for­mance in­clud­ing the sta­bil­i­ty and re­peata­bil­i­ty of the mea­sure­ment and the in­flu­ence of the laser pa­ram­e­ters. We will also dis­cuss novel beam di­ag­nos­tics ca­pa­bil­i­ties at the SNS SCL by using the laser wire sys­tem.


* Liu et al., "Laser wire beam profile monitor in the SNS superconducting linac," Nucl. Instr. and Meth. A, to appear.

  
THPEB039 SNS Stripper Foil Failure Modes and Their Cures 3969
 
  • M.A. Plum, J. Galambos, S.-H. Kim, P. Ladd, Y. Polsky, R.W. Shaw
    ORNL, Oak Ridge, Tennessee
  • C.F. Luck, C.C. Peters
    ORNL RAD, Oak Ridge, Tennessee
  • R.J. Macek
    LANL, Los Alamos, New Mexico
  • D. Raparia
    BNL, Upton, Long Island, New York
  
 

The di­a­mond strip­per foils in use at the Spal­la­tion Neu­tron Source worked suc­cess­ful­ly with no fail­ures until May 3, 2009, when we start­ed ex­pe­ri­enc­ing a rash of foil fail­ures after in­creas­ing the beam power to ~840 kW. The main con­tri­bu­tions to foil fail­ure are thought to be 1) con­voy elec­trons, stripped from the in­com­ing H− beam, that strike the foil brack­et and may also re­flect back from the elec­tron catch­er, and 2) vac­u­um break­down from the charge de­vel­oped on the foil by sec­ondary elec­tron emis­sion. In this paper we will de­tail these and other fail­ure mech­a­nisms, and de­scribe the im­prove­ments we have made to mit­i­gate them.