Injector/BC1 Commissioning (Jan. 2006 through Aug. 2007) P. Emma, et al. LCLS DOE Review Oct. 25, 2006 LCLS http://www-ssrl.slac.stanford.edu/lcls/internals/commissioning/index.html

LCLS Accelerator Schematic 6 MeV z  0.83 mm   0.05 % 135 MeV z  0.83 mm   0.10 % 250 MeV z  0.19 mm   1.6 % 4.30 GeV z  0.022 mm   0.71 % 13.6 GeV z  0.022 mm   0.01 % Linac-X L =0.6 m rf= -160 Linac-0 L =6 m rf gun L0-a,b Linac-1 L 9 m rf  -25° Linac-2 L 330 m rf  -41° Linac-3 L 550 m rf  0° 25-1a 30-8c ...existing linac 21-3b 24-6d 21-1 b,c,d undulator L =130 m X BC1 L 6 m R56 -39 mm BC2 L 22 m R56 -25 mm DL1 L 12 m R56 0 DL2 L =275 m R56  0 Commission in Jan. 2007 Commission in Jan. 2008 SLAC linac tunnel research yard

Complete & Detailed Optics (cathode to dump) BC2 L3 LTU undulator sec-21 sec-30 Full MAD files at: http://www-ssrl.slac.stanford.edu/lcls/linac/optics/

LCLS Installation and Commissioning Time-Line Drive-Laser Commissioning LTU/und. Install Drive-Laser Installed Controls Checkout LTU/und. hall “ready” First Spont. Light A S O N D J F M A M J J A S O N D J F M A M J J 2006 2007 2008 Gun/Inj./BC1 Install (8/21 – 2/20) Gun/Inj./BC1 Commissioning linac/BC2 Commissioning linac/BC2 Install LTU/und. Commissioning Oct. 18, 2006

LCLS Injector Commissioning Dates (2006 - 2007) Dec 18: PPS Certified Dec 20-Jan 1: Holidays Jan 2: VVS’s switched on for PEP-II (RF power available) Jan 15: L0a, L0b, L1 RF processing begins Feb. 1: X-band RF processing begins Feb 20: GTL beamline installation complete Mar 6: Virtual cathode fully characterized (ready to install gun) Mar 7: RG gun installation begins – laser rate to 30 Hz Mar 16: First laser UV-light on cathode! Mar 17: Electrons in GTL and gun-spectrometer Apr 9: Beam through L0a, L0b and down to 135-MeV spectrometer Apr 24: Beam into main linac (to TD11 dump) ~July: Take beam down full linac (to BSY SL2 stopper) http://www-ssrl.slac.stanford.edu/lcls/internals/commissioning/documents/commissioning-dates-2006-2007.ppt

Commissioning Definition and Strategy All components installed, aligned, connected, and initially verified by system engineer, before commissioning starts. Commissioning Sequence – Layered Approach (0-3) 0. Pre-Beam Checkout (tunnel, gallery, control room) Controls/software testing, camera checks, beamline inspection, etc Magnet polarities, cable connections, verify motion-control, etc Beam-based Hardware and Software Checkout Establish beam transport, RF setup, MPS/BCS tests, etc Checkout of all BPMs, magnets, wires, screens, toroids, etc First-Order Optics: Measurement and Correction Steering, transmission, oscillation data, feedback setup, etc Beta and dispersion matching, beam-base align key quads, etc Full Beam Characterization: Measurement and Correction Measure emittance, energy spread, distributions - correct Measure beam sensitivities, optimize tuning, beam experiments No (serious) emittance measurements until all hardware/software checked out!

(detailed schedule available) pass-1 pass-2 pass-3 pass-1 pass-2 pass-3

http://www-ssrl. slac. stanford http://www-ssrl.slac.stanford.edu/lcls/internals/commissioning/documents/2007-commissioning-plan.doc

LCLS Injector Commissioning Day 24-Hour Cycle (7 days/week, 1/2/07 to 8/31/07, 35 total weeks) DAY SHIFT (8:00-16:00) 1 lead physicist, 1 physicist, 1 controls eng., 1 sys. engineer, 1 LCLS operator, 1 laser operator SWING SHIFT (16:00-24:00) 1 lead physicist, 1 physicist, 1 LCLS operator, 1 laser operator OWL SHIFT (0:00-8:00) 1 LCLS operator, 1 laser operator ?

Personnel Available for LCLS Injector/BC1 Commissioning Shift Leaders (initially) (1 per D/S shift) Dave Dowell Paul Emma Jim Turner Bill White (laser) Joe Frisch Cecile Limborg Controls eng. (1 per DAY shift) Stephanie Allison Mike Zelazney Debbie Rogind Diane Fairley Stephen Norem Arturo Alarcon Doug Murray Sergei Chevtsov Dayle Kotturi Patrick Krejcik Kristi Luchini Sheng Peng Stephen Schuh Till Straumann Sys. Engineers (1 per DAY shift) Eric Bong Carl Rago Leif Eriksson Richard F. Boyce Jose Chan Tim Montagne Paul Bellomo Antonio de Lira Dave MacNair Ron Akre LCLS Physicists (1 per D/S shift) Sasha Gilevich Henrik Loos Heinz-Dieter Nuhn John Schmerge Dave Schultz Jim Welch Juhao Wu Accelerator, ILC, SSRL Franz-Josef Decker Rick Iverson Doug McCormick Jeff Corbett James Safranek... Operations (1 per DAY & SWING shift and 2 per OWL) Laser Operators (4-5) Visitors ?

Manpower Requirements (1/2/07 - 8/31/07) 35 weeks total (1/2/07 to 8/31/07, minus 2 weeks) 80% coverage (downtime) 14 lead-physicist shifts/week 14 physicist shifts/week 7 controls eng. shifts/week 7 sys. engineer shifts/week Average of 2-3 shifts/week for each physicist Average of 1/2 shift/week for each controls eng. Average of 1 shift/week for each sys. engineer

LCLS Commissioning Parameters Value Comments RF rate 10-30 Hz 10 Hz in linac with possible 30-Hz rate - 120 Hz in gun for short time to verify full rate Beam rate ≤30 Hz 30 Hz e- beam as baseline – possible short term 120-Hz tests in L0-BC1 for feedback tests, etc Drive-laser rate 30 Hz 120-Hz during laser commissioning – 30 Hz during e- commissioning - shutters provide lower e- rate Bunch charge 200-500 pC depends on QE and diagnostics – some short spans at 10 pC – later in ’07 explore 1-nC Drive-laser pulse length 10 ps fwhm 10-ps fwhm startup with possibility of 6-ps at 0.2 nC Gun gradient 120 MV/m Set as goal, although 110 MV/m is adequate in ‘07

Issues Controls will be mixed (SLC, Epics, Matlab) and capabilities may be limited initially (H. Shoaee) Most High-Level Applications (emittance, bunch length, feedback) done through MATLAB as temporary solution Many LCLS physicists not experienced with existing SLC controls Help from operations group is essential

RF Photo-Cathode Gun Q  1 nC f  120 Hz e- G  120 MV/m gex,y  1 mm Dt  10 ps I  100 A E  6 MeV e- spec. dipole e- UV laser solenoid YAG screens RF gun cathode

Injector Diagnostics YAG screen RF Gun trajectory (BPMs) emittance (+ slice) energy spread (+ slice) bunch length (+ dist.) charge (+ dark current) YAG screen YAG screen YAG screen YAG screen gun spectrometer Transverse RF deflector OTR & wire Injector Diagnostics OTR & wire OTR & wire OTR & wire main SLAC Linac injector spectrometer YAG YAG & OTR

Straight Ahead Spectrometer Bunch Length Diagnostics Injector Through BC1 RF Gun & Solenoid L0a&L0b S-Band Linacs Transverse RF Cavity Bunch-Compressor-1 (BPM, OTR, collimator) OTR & Wire Scanners Gun Spectrometer L1 S-Band Linac Wire Scanners + OTR 135 MeV 250 MeV TD-11 stopper X-Band RF Straight Ahead Spectrometer Bunch Length Diagnostics 40 m

Accelerator Sections Straightened Coordinate Measurement Machine (CMM) after before (De/e  30%) Four RF sections measured on CMM and straightened (L0a, L0b, L1a, L1b) Jose Chan

Magnet Polarities Defined and Documented DIPOLES QUADRUPOLES SOLENOIDS

BPMs, Wire-Scanners, etc. Polarities Defined q = 0 q = +45º q = -45º q = +45º

All Magnets Measured (all steering coil ‘types’) 2 Solenoids 19 Inj. Quads 2 GTL Quads 2 BC1 Quads 3 Linac Quads 2 DL1 Dipoles 4 BC1 Dipoles 2 Spect. Bends 6 corr. types Dipole field vs. x Current vs. integrated field FINT = 0.454 Solenoid eff. length Dipole fringe field vs. z + field harmonics

BC1 Chicane tweaker quad 2 0-30 cm translation stage tweaker quad 1 OTR X-band RF collimator BPM

BC1 Dipole Fields are Marginal tracking through fields measured with stretched wire De/e0  1 to 6 % Pole nose pieces in fabrication + tweaker quadrupoles available

Dispersion Correction in SPPS Chicane One linear comb. of 2 tweaker quads

Pre-Beam Tunnel Check List etc.

Summary Injector e- commissioning starts Mar. ’07 Main ’07 goal is to verify full functionality of gun, injector beam-line, diagnostics, and controls, not generate full beam brightness immediately Will need frequent linac access initially (8-16 hrs/week?) + 1 install-day per month (24-48 hrs?) Phase-II of commissioning comes in Dec. ’07 Information available at commissioning web-site: http://www-ssrl.slac.stanford.edu/lcls/internals/commissioning/index.html