Paul Emma LCLS FAC April 16, Initial Experience with Injector Commissioning P. Emma, et al. Facilities Advisory Committee Meeting April 16, 2007 LCLS

Paul Emma LCLS FAC April 16, ~45 m (150 ft) RF Gun & Solenoid + YAG screens GunSpectrometer L0a&L0b S-Band Linacs OTR & Wire Scanners Straight Ahead Spectrometer Transverse RF Cavity L1 S-Band Linac Bunch-Compressor-1 (BPM, OTR, collimator) Wire Scanners + OTR Bunch Length Diagnostics X-Band RF TD11stopper 135 MeV 250 MeV LCLS Injector Through BC1 6 MeV

Paul Emma LCLS FAC April 16, Electron Beam Transported to All Injector Areas April 5: First photo-electrons from gun (6 MeV) April 5: First e  to gun spectrometer (6 MeV) April 8: First e  to inj-spectrometer (127 MeV) April 9: First e  in linac to TD11 dump (127 MeV) April 14: First 250-MeV beam through BC1 Up to ~330 pC of charge (370 µJ laser energy) 10 Hz beam & 30 Hz RF (30 Hz e  also tested) Gun RF feedback running well (+ water)

Paul Emma LCLS FAC April 16, Pre-Beam Tunnel Check List Almost Complete etc. etc. 40 pages, ~2000 checks – all DONE (except a few missing screens) Serial numbers Polarity conventions Installation orientation Field type (quad, dipole)

Paul Emma LCLS FAC April 16, RF Processing of L0b (20-8) March 10 March 25 Thanks to R. Akre & AMRF

Paul Emma LCLS FAC April 16, Gun Temperature Feedback Loop Gun Temperature Gun RF Probes RF On RF OffRF On Thanks Phil Cutino, Claudio Rivetta, Joe Frisch

Paul Emma LCLS FAC April 16, µsec Gun RF coupler (input power) Gun Reflected Power Gun RF probe (cavity power) Thanks Arnold Vlieks 11 MW (~120 MV/m) Gun RF Power (30 Hz) Time laser here with diode

Paul Emma LCLS FAC April 16, Virtual Cathode (optical image of laser spot on cathode)

Paul Emma LCLS FAC April 16, Beam on YAG02 (80 cm from gun) 20 mm

Paul Emma LCLS FAC April 16, Laser Phase (Shottky) Scan 30º 50 µJ laser energy

Paul Emma LCLS FAC April 16, Beam on Gun Spectrometer 5.7 MeV

Paul Emma LCLS FAC April 16, Beam to Injector Spectrometer 135 MeV BPMs worked almost immediately! energy GUN Steering was easy with few correctors on strong SDMP

Paul Emma LCLS FAC April 16, Trajectory to TD11 (in main linac) GUN TD11 DL1 energy BPM oldBPM BPMs worked almost immediately! oldBPM BC1BPM BC1 energy BPM

Paul Emma LCLS FAC April 16, L0a RF Phase Scan on Dispersed BPM X L0a RF phase (deg-S) high energy Spect. BPM X Reading after Bend (mm)

Paul Emma LCLS FAC April 16, Bunch Charge vs. Laser Energy calibrations need confirmation Iris cut clips laser energy 330 pC 370 µJ at cathode

Paul Emma LCLS FAC April 16, EPICS Controls - Vacuum Manual valve

Paul Emma LCLS FAC April 16, EPICS Controls - Magnets

Paul Emma LCLS FAC April 16, EPICS Controls – Profile Monitors

Paul Emma LCLS FAC April 16, Long Ion Chamber Along Full Accelerator YAG03 inserted YAGS2 inserted

Paul Emma LCLS FAC April 16, Charge and Position Jitter – Shot to Shot 100 shots at 10 Hz using BPM immediately after gun X-position jitter is 10 µm rms 20 µm Charge jitter is 2.6% rms 2%

Paul Emma LCLS FAC April 16, BC1 Chicane Control and Compression RF phase:  40º RF phase: 0º RF phase:  40º Ceramic Gap Bunch Length Monitor BC1 X-Mover (mm) BC1 BPM X (mm) OTR screen still needs camera Slope = MeV when X = 0 BPM offset checked using BC1 collimator jaws to locate beam in X

Paul Emma LCLS FAC April 16, Problems/Issues Gun Faraday cup broken (pneumatic error) Gun toroid shorted during installation Gun z-position not right yet (7.5-mm interference) YAG screens not setup before installation (hard-stops) Still need to install cameras and air lines for 7 screens No toroids working yet (1 shorted, 3 left to install) BC1 motion control limited (300 mm  260 mm) QE about 4-times lower than design (to be verified) Some controls tools late (orbit displays & fitting) MCOR power supply ADC readback noise (~1%)

Paul Emma LCLS FAC April 16, Injector Commissioning Goals ssrl.slac.stanford.edu/lcls/internals/commissioning/documents/l clsinjector-commissioninggoals.doc

Paul Emma LCLS FAC April 16, Summary Beam transported to all areas (no trouble) No obstructions or ‘backwards’ components, etc (but no systematic checkout yet) Controls still developing, but working well and improving fast – great cooperation and effort Communication with laser group excellent Screens and toroids late, but installation continues Some quality control issues with a few components Thanks to all – First indications are very positive