1. Hal Tompkins – Photon Beam Systems Deputy June 8, 2009
FEE Commissioning
Hal Tompkins – Photon Beam Systems Deputy
June 8, 2009

2. First beam into FEE late June/early July First beam into NEH late July
Beam Schedule
First beam into FEE late June/early July
First beam into NEH late July
First scheduled user run Sep-Dec.
CD 4 goal of beam to FEH accomplished March, 2010

3. FEE Layout Beam Direction Solid Attenuators Gas Attenuator
Thermal Sensor
Beam Direction
Slit
Gas Detectors
K-Mono
5 mm collimator
Direct Imager
(Scintillator)
FEL Offset Mirror Systems

4. Interim FEE Layout

5. Phase 1 Commissioning
Commissioning time must be shared between electron and photon halves
Reliable lasing at all wavelengths has already been demonstrated
B4C testing is part of commissioning
Deposited power is greatest at 830 eV operation - estimated dose to B4C at ST1 is .35 eV/atom, melt dose is calculated at .63 eV/atom
B4C testing in ST0 chamber took place in May - this location is 48 m from end of undulator
B4C target is continuously monitored with camera at MCC for damage - log entries required on daily basis

6. Phase 1 Commissioning
Cen.
Ref.

7. Phase 1 commissioning (cont.)
Requirements for allowing beam to FEE:
FEE included in expanded SAD/ASE which is being reviewed internally at SLAC
Accelerator Systems Division (ASD) responsible for operation of FEE
FEE PPS certified
RP survey plan based on LCLS commissioning plan
Beam Authorization Sheet for FEE

8. Phase 1 Commissioning (cont.)
Requirements for allowing beam to FEE (cont.):
B4C “moveable mask” installed upstream of FEE stoppers (ST1 and ST2)
Direct Imager YAG screen permanently installed in beam path
C1 Collimator installed in planned location
Temporary beam dump (B4C and W alloy) installed on differential pump stand
Two protection ion chambers (PIC’s) downstream of C1 and two more downstream of temporary dump
Air gap of 20 cm
Three pairs of hutch stoppers with BTM’s active and stoppers locked closed installed in planned location
C3 collimators installed in planned location
Shadow wall and wall 2 window installed

9. Phase 1 Commissioning (cont.)

10. Phase 1 Commissioning (cont.)
Installation in downstream half of FEE can proceed during day shift, in parallel with B4C testing in ST0 can
Diagnostics and FEL commissioning can proceed during swing and owl shifts
ASD will have to search and secure the FEE every day
Upstream half of FEE will require RSWCF for breaking vacuum
Damage to Direct Imager YAG screen requires immediate inspection of C1 and temporary beam dump
Target date for beam to FEE is late June/early July
C1, C3 collimators
FEE PPS

11. Phase 1 Commissioning (cont.)
Overall diagnostics commissioning plan has needed revision - nobody expected immediate lasing at 1.5 Ang.
Diagnostics commissioning still begins with Direct Imager - want spontaneous radiation
Open FEE stoppers - follow RP survey plan
Begin with adjustable slits closed
B4C apertures in attenuator rafts open
Slowly open adjustable slits - verify proper slit operation
Verify 25 mm x 45 mm fixed mask aperture
Insert B4C apertures singly, then each raft.
Raft alignment best done with FEL - be careful to keep YAG below saturation

12. Soft X-ray spontaneous from full undulator (calculated)
As seen in Direct Imager, using 5 µm YAG

13. Hard X-ray spontaneous, from full undulator (calculated)
As seen in Direct Imager, using 50 µm YAG

14. Soft X-ray FEL signal in Direct Imager
As seen in Direct Imager, using 5 µm YAG
Peak pixel has 160 photoelectrons / nJ of FEL

15. Phase 1 Commissioning (cont.)
Commission gas detectors - use FEL
Add nitrogen gas to detector volume
Power magnet
Compare APD & PMT response to changes in intensity
Repeat at several different photon energies/gas pressures
Commission gas attenuator - interleaved with gas detector commissioning
Commission K-monochromator
Transmit beam through 4 bounces (~8.172 eV)
Check out quadrant photodiode
Confirm Ni foil calibration of linac energy

16. Phase 1 Commissioning (cont.)
Commission Total Energy detector
Pulse energy already measured to be ~1-2 mJ by electron side with ~50% error bars
This measurement is good enough to claim CD 4 goal of 106 photons/mm2-0.1%BW-pulse (though technically it was not made in the FEE)
TEM should be accurate to 5-10%
Pulse energy measurement is crucial for B4C testing confidence
Once total energy monitor is commissioned, cross-calibrate the gas detectors and the direct imager
This needs to be done at multiple energies - emphasis on the eV range
It also needs to be done at multiple intensities - but we must protect the YAG

17. Beam to downstream half of FEE
Phase 2 Commissioning
Beam to downstream half of FEE
Very useful for commissioning pop-in monitors and offset mirror systems - can commission through P3’s
Will require agreement from RSO that B4C test piece in ST0 can has seen sufficient number of FEL pulses to justify confidence in B4C being “FEL-proof”
Some fraction of commissioning time will continue to be spent dumping pulses into ST0 test mask
FEL will terminate at hutch stoppers S1, S2, and SH1 or B4C-protected collimators

18. HOMS and SOMS mounts share a common design
With temperature controlled to 0.01 deg, pointing stability is better than 10 nrad

19. HOMS: Hard x-ray Offset
LCLS Offset Mirror Systems
HOMS: Hard x-ray Offset
Mirror System eV
to Hutch 1
SOMS: Soft x-ray Offset
Mirror System eV
to Hutch 2

20. NEH Commissioning NEH beam steps Beam to NEH in late July
NEH ARR June 30-July 1
AMO IRR mid-July
Hutch HPS certified
XFD Operations procedures in place, reviewed, and approved by SLAC
24/7 floor coordinator coverage in place
Beam Line Authorization for Hutch 1
AMO beam containment plan approved by RSO
Beam to NEH in late July

21. First beam into FEE late June/early July
Summary
First beam into FEE late June/early July
First beam into NEH in late July
First scheduled user run Sep-Dec
CD 4 goal of beam to FEH March, 2010