Initial Commissioning Tasks for the LTU/FEL Run (2008-2009)
Oct. 27, 2008
The First Four Weeks (Nov. 3-28, 2008)
Goal #1:Re-establish beam to 52-SL2 at 30 Hz & 0.25 nC
Goal #2:Release and test all new controls software updates that are ready
Goal #3:Begin commissioning of laser heater system (w/o undulator)
- All injector, linac, and BSY pre-beam checkout done and all magnets standardized to startup configs (SCORE: Gun-TD11 Gold #2103, TD11-BSY Gold #2174, and for the SCP: TD11-BSY magnets NOR #141, BPM-ref NOR #207 – see R. Iverson)
- No unnecessary new controls software released yet
- RF processing of gun and injector RF (gun separated from L0a/b with VV01)
- See Axel Brachmann’s procedure (6.0 MV max. gun voltage)
- Check RF trip power interlock
- Note TCAV0 (20-5) was vented and 21-1 klystron was replaced
- Re-establish UV drive laser on VCC and cathode with 1.2-mm iris and ~20µJ
- Run through laser checklist (laser timing will start random) – 6.0 ps
- Re-GOLD (if necessary) and switch ON the laser pointing feedback loops
- Take 0.25-nC beam to 6-MeV spectrometer (1-10 Hz)
- Injector vault fan switched off?
- Wide range Schottky scan
- Image cathode on YAG01 and verify cathode position (no “spider”)
- Measure QE
- Align laser using solenoid-scan GUI (with Aug. ’08 offsets)
- Steer to YAGG1
- Calibrate gun RF amplitude on YAGG1 (6-MeV spectrometer)
- Measure energy spread on YAGG1 vs. laser phase
- Re-GOLD (if necessary) and switch ON the following feedback loops:
- Laser Power Set
- Bunch charge
- Take 0.25-nC beam to 135-MeV spectrometer (1-10 Hz, see procedure)
- Make sure BXS is properly standardized (with trim coil OFF, then set to 1.06 A)
- New laser-heater chicane OFF, LH-undulator not installed, and no IR laser
- Rough steer in x and y
- Check PH01 timing reading (see R. Akre) – maybe shift laser timing?
- Phase and calibrate L0a amplitude on YAGS2 (135-MeV spectrometer)
- Phase and calibrate L0b amplitude on YAGS2 (135-MeV spectrometer)
- Check YAGS2 for “on-crest” operation with TCAV0 ON (no linear chirp)
- Fine steer in x and y
- If time allows, measure OTR2 Twiss emittance and run β-matching, and correct any induced steering (after matching)
- If time allows, measure bunch length on OTR2 with TCAV0
- Re-GOLD (if necessary) and switch ON injector feedback loops:
- Gun launch
- Injector launch
- Take beam to TD11 stopper with BC1 ON at R56 = 45.5 mm, BC1 offset = 247.6 mm, and energy = 250 MeV (1-10 Hz)
- Adjust L1S phase (& voltage?)roughly to get beam through BC1 (L1X OFF)
- Steer beam reasonably flat in x and y using minimal corrector tweaks
- Calibrate L1S amplitude at crest phase using the BC1 BPM (L1X OFF)
- Re-GOLD and switch ON BC1 energy feedback (with DL1 energy, but no BC1 bunch length yet)
- Calibrate L1X amplitude at decal-crest phase usingthe BC1 BPM (scan L1X voltage and correlate withL1S voltage feedback response needed to hold BC1 BPM constant in x)
- Re-GOLD (with BPMS LI21 201x = +0.1 mm) and switch ON X-cavity launch feedback loop (leave BPM offset unchanged)
- Phase L1S OFF crest by 21 degrees (see OP GUI)
- Phase L1X OFF crest by 160 degrees (see OP GUI)
- Check BL11 mirror is inserted (no filters INserted)
- Test BL11A response to L1S phase?
- If ready, re-GOLD (if necessary) and switch ON BC1-bunch-length feedback loop (+ DL1-energy + BC1-energy)
- Checkout injector BPM timing, attenuation, and reasonable response to a few oscillations (any BPMs now backwards or not responding in x, y, or TMIT?)
- Take beam to 52-SL2 stopper at 13.64 GeV with BC2 ON at R56 = 24.7 mm, BC2 offset = 363.0 mm, and BC2 energy = 4.3 GeV (1-10 Hz)
- Standardize LI21 quadrupole and corrector magnets
- Open all 29/30 collimators (+-10 mm)
- Note sec-21, 23, 29, & 30 (especially) are at random phases
- CTRL-C the “phase_control.m” script and phase and GOLD all 21-24 KLYS & SBST using SCP (see J. Frisch)
- Add or remove klystrons to get beam through BC2 (or vary phases?)
- Phase all RF stations (25-1 to 30-8, with all SBST PDES = 0)
- Set L2 RF phase to 36 deg using phase-scan GUI
- Run phase scans on 24-1 & 24-2 (and more?)
- Steer linac to BPM ref (note sec-22 through 23 now have EPICS control of quads & steering correctors - also ON SCP but LI23 feedback anymore)
- Check BL21 mirror is inserted
- Re-GOLD (if necessary) and switch ON linac/energy feedback loops:
- L2 launch
- LI26 SCP loop
- DL1-energy, BC1-energy, BC1-bunch-length, BC2-energy, and BC2-bunch-length
- FB31 energy loop
- Measure and correct emittance and matching at OTR2, WS12, and WS28 and re-establish good orbit, bunch compression, and stability at 30 Hz (0.25 nC)
- Begin controls software releases and testing…
- New MPS commissioning? (start with old MPS first)
- Laser BSA deployment
- Laser bug fixes (phase jumps)
- New L3 PACs
- Phase cavity software
- New L3 energy feedback
- Updated GUIs where needed
- etc…
- Install laser-heater undulator on 8-hr ROD in mid-late November
- Begin laser-heater chicane and IR laser testing…
- Match beam on OTR2 with heater OFF (undulator not installed)
- Turn ON heater chicane (35 mm X-offset at 135 MeV) with GUI and note/correct steering (beam to 135-MeV spectrometer)
- Check that injector phase is compensated properly by GUI
- Re-check OTR2 beam matching and correct again (note quad changes)
- Verify heater MPS logic (?)
- Find IR beam on OTRH1 & OTRH2 (laser attenuated to <1 µJ)
- Steer electron beam to same location on OTRs
- Time IR beam to electron beam using photodiode and scope locally
- Set laser energy to ~40 µJ (OTRs out, blocked photodiode)
- Look for energy spread increase on YAGS2 (TCAV0 ON) while scanning IR delay
December (or January) 2008
Goal #1:Establish beam to the main LCLS dump(if areas ready)
Goal #2:Finish RP commissioning tasks in LTU/dump(if areas ready)
Goal #3:Fully commission laser heater system and measure COTR impact
- Take beam to D-2 dump at 13.6 GeV (1-10 Hz)
- Execute RP commissioning plan for undulator complex:
January (or February) 2008 and Beyond
Goal #1:Commission LTU, Undulator, Dump, and FEE
Goal #2:Measure and Optimize SASE FEL power at 15 Å and below
Goal #3:Setup machine for AMO experiments in August 2009 (30 Hz)
- Install undulators in mid-March
- Take x-rays into FEE after May 14 , 2009
- Go to Goose (and stay)