Author: Luchini, K.
Paper Title Page
TUCAUST04 Changing Horses Mid-stream: Upgrading the LCLS Control System During Production Operations 574
 
  • S. L. Hoobler, R.P. Chestnut, S. Chevtsov, T.M. Himel, K.D. Kotturi, K. Luchini, J.J. Olsen, S. Peng, J. Rock, R.C. Sass, T. Straumann, R. Traller, G.R. White, S. Zelazny, J. Zhou
    SLAC, Menlo Park, California, USA
  
  The con­trol sys­tem for the Linac Co­her­ent Light Source (LCLS) began as a com­bi­na­tion of new and lega­cy sys­tems. When the LCLS began op­er­at­ing, the bulk of the fa­cil­i­ty was newly con­struct­ed, in­clud­ing a new con­trol sys­tem using the Ex­per­i­men­tal Physics and In­dus­tri­al Con­trol Sys­tem (EPICS) frame­work. The Lin­ear Ac­cel­er­a­tor (LINAC) por­tion of the LCLS was re­pur­posed for use by the LCLS and was con­trolled by the lega­cy sys­tem, which was built near­ly 30 years ago. This sys­tem uses CAMAC, dis­tribut­ed 80386 mi­cro­pro­ces­sors, and a cen­tral Alpha 6600 com­put­er run­ning the VMS op­er­at­ing sys­tem. This lega­cy con­trol sys­tem has been suc­cess­ful­ly up­grad­ed to EPICS dur­ing LCLS pro­duc­tion op­er­a­tions while main­tain­ing the 95% up­time re­quired by the LCLS users. The suc­cess­ful tran­si­tion was made pos­si­ble by thor­ough test­ing in sec­tions of the LINAC which were not in use by the LCLS. Ad­di­tion­al­ly, a sys­tem was im­ple­ment­ed to switch con­trol of a LINAC sec­tion be­tween new and lega­cy con­trol sys­tems in a few min­utes. Using this rapid switch­ing, test­ing could be per­formed dur­ing main­te­nance pe­ri­ods and ac­cel­er­a­tor de­vel­op­ment days. If any prob­lems were en­coun­tered after a sec­tion had been switched to the new con­trol sys­tem, it could be quick­ly switched back.  
slides icon Slides TUCAUST04 [0.183 MB]  
 
FRBHAULT03 Beam-based Feedback for the Linac Coherent Light Source 1310
 
  • D. Fairley, K.H. Kim, K. Luchini, P. Natampalli, L. Piccoli, D. Rogind, T. Straumann
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the U. S. Department of Energy Contract DE-AC02-76SF00515
Beam-based feed­back con­trol loops are re­quired by the Linac Co­her­ent Light Source (LCLS) pro­gram in order to pro­vide fast, sin­gle-pulse sta­bi­liza­tion of beam pa­ram­e­ters. Eight trans­verse feed­back loops, a 6x6 lon­gi­tu­di­nal feed­back loop, and a loop to main­tain the elec­tron bunch charge were suc­cess­ful­ly com­mis­sioned for the LCLS, and have been main­tain­ing sta­bil­i­ty of the LCLS elec­tron beam at beam rates up to 120Hz. In order to run the feed­back loops at beam rate, the feed­back loops were im­ple­ment­ed in EPICS IOCs with a ded­i­cat­ed eth­er­net mul­ti­cast net­work. This paper will dis­cuss the de­sign, con­fig­u­ra­tion and com­mis­sion­ing of the beam-based Fast Feed­back Sys­tem for LCLS. Top­ics in­clude al­go­rithms for 120Hz feed­back, mul­ti­cast net­work per­for­mance, ac­tu­a­tor and sen­sor per­for­mance for sin­gle-pulse con­trol and sen­sor read­back, and feed­back con­fig­u­ra­tion and run­time con­trol. 		 
slides icon Slides FRBHAULT03 [1.918 MB]