1. Injector/BC1 Commissioning (Jan through Aug. 2007) P. Emma, et al. LCLS DOE Review Oct. 25, 2006
LCLS

2. 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  mm
  0.71 %
13.6 GeV
z  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

3. Complete & Detailed Optics (cathode to dump)
BC2 L3
LTU
undulator
sec-21
sec-30
Full MAD files at:

4. 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

5. 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)

6. 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!

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

8. http://www-ssrl. slac. stanford

9. 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 ?

10. 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 ?

11. 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

12. LCLS Commissioning Parameters
Value
Comments
RF rate
10-30 Hz
10 Hz in linac with possible 30-Hz rate 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 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. Magnet Polarities Defined and Documented
DIPOLES
QUADRUPOLES
SOLENOIDS

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

20. 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

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

22. 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

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

24. Pre-Beam Tunnel Check List
etc.

25. 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: