• B. Hong, R. Akre, V. Pacak
  SLAC, Menlo Park, California

The Linac Co­her­ent Light Source (LCLS) at SLAC is in full user op­er­a­tion and has met the sta­bil­i­ty goals for sta­ble las­ing. The 250pC bunch can be com­pressed to below 100fS be­fore pass­ing through an un­du­la­tor. In a new mode of op­er­a­tion a 20pC bunch is com­pressed to what is be­lieved to be about 10fS. Ex­per­i­menters are reg­u­lar­ly using this short­er X-ray pulse and get­ting pris­tine data. The 10fS bunch has tim­ing jit­ter on the order of 100fS. Physi­cists are re­quest­ing that the RF sys­tem achieve bet­ter sta­bil­i­ty to re­duce tim­ing jit­ter. Drifts in the RF sys­tem re­quire lon­gi­tu­di­nal feed­backs to work over large ranges and er­rors re­sult in re­duced per­for­mance of the LCLS. This paper de­scribes the new RF sys­tem being de­signed to help di­ag­nose and re­duce jit­ter and drift in the SLAC linac.