LCLS Commissioning Parameters for Phase-5 (NEH) Parameter Value Comments RF rate 30 Hz 30 Hz in linac - 120 Hz in gun hot test Beam rate ≤30 Hz 30 Hz e- beam as baseline – 10 Hz or lower when needed – 120 Hz testing when possible Drive-laser rate 30 Hz during e- commissioning - shutters provide lower e- rate Bunch charge 0.2-1 nC 0.2 nC nominal – up to 1 nC or well below 0.2 nC as desired for optimizing brightness Drive-laser pulse length 6 ps fwhm 6-ps fwhm at 0.2 nC, but variable with charge when needed Gun gradient 120 MV/m Baseline level, as used in ’07 and ’08 already July 29, 2009