A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Polsky, Y.

Paper Title Page
TUPEA028 Beam Stop Design Methodology and Description of a New SNS Beam Stop 1384
 
  • Y. Polsky, P.J. Geoghegan, L.L. Jacobs, S.M. McTeer, M.A. Plum
    ORNL, Oak Ridge, Tennessee
  • W. Lu
    ORNL RAD, Oak Ridge, Tennessee
  
 

The use of a beam stop to ab­sorb full or par­tial beam at var­i­ous points along a par­ti­cle ac­cel­er­a­tor is com­mon­place. The de­sign of ac­cel­er­a­tor com­po­nents such as mag­nets, linacs and beam in­stru­ments tends to be a fair­ly fo­cused and col­lec­tive ef­fort with­in the par­ti­cle ac­cel­er­a­tor com­mu­ni­ty with well es­tab­lished per­for­mance and re­li­a­bil­i­ty cri­te­ria. Beam stop de­sign by con­trast has been rel­a­tive­ly iso­lat­ed and un­con­strained his­tor­i­cal­ly with much more gen­er­al goals. This com­bi­na­tion of con­di­tions has lead to a va­ri­ety of fa­cil­i­ty im­ple­men­ta­tions with vir­tu­al­ly no stan­dard­iza­tion and min­i­mal con­cen­sus on ap­proach to de­vel­op­ment with­in the par­ti­cle ac­cel­er­a­tor com­mu­ni­ty. At the Spal­la­tion Neu­tron Source (SNS), for ex­am­ple, there are four high power beam stops in use, three of which have sig­nif­i­cant­ly dif­fer­ent de­sign so­lu­tions. This paper de­scribes the de­sign of a new off-mo­men­tum beam stop for the SNS. Con­tent will be bal­anced be­tween hard­ware de­scrip­tion, anal­y­ses per­formed and the method­ol­o­gy used dur­ing the de­vel­op­ment ef­fort. Par­tic­u­lar at­ten­tion will be paid to the ap­proach of the de­sign pro­cess with re­spect to fu­ture ef­forts to meet beam stop per­for­mance met­rics.

  
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.