Startup and Commissioning Plans after the
March 2009 Undulator Installation
April 6, 2009
Goal #1:
Goal #2:
Date of Startup:
Checkout Undulators
Demonstrate First FEL Light
April 6, 2009 (tentative)
1. Pre-beam checkout of all installed undulators (Nuhn, Welch, Controls). DONE
2. Start with all 21 installed undulators (#13 to #33?) fully retracted (+80 mm) and
ST1 & ST2 locked IN as required in BAS (YAGXRAY screen and Nickel foil
installed in ST0 can).
3. Check girder position and undulator magnet SCORE configs to be sure all
undulator settings are nominal (still with all 21 installed undulators retracted).
Possibly the ±60 µm horizontal Earth’s field alternating offsets of the undulator
quadrupoles will be corrected before beam (Welch & Nuhn to determine).
4. First 2-3 days to re-establish beam to the main dump at 13.6 GeV. Check linac &
LTU collimators, and with TDUND closed verify beam size on LTU wirescanners is OK, then take beam through undulator very carefully (1 Hz, 50 pC, all
screens OUT, etc).
5. Verify MPS is connected and working, generating as little real beam loss as
possible (BPMs, BLMs, toroid comparator, etc). Also make sure we are running
Joe’s “Guardian” supplemental MPS script.
6. Minimize beam shots in the undulator until MPS is reasonably verified, unless in
process of verifying or first establishing beam to dump.
7. Steer undulator orbit (still with all segments retracted) and record the necessary
changes (steering GUI available, but may need human intervention in this case).
Check dump steering and OTRDMP image as well. Try to move the BYD SR
stripe out of the region of interest using YCUE2 or YCD3. [1 hr]
8. Re-run BBA with all segments retracted and record girder and BPM offset
adjustments. [4-8 hrs]
9. Re-run BFW alignment with all segments retracted and record girder adjustments.
[4-8 hrs]
10. Insert one undulator at a time, starting with #33 and working backwards (retract
one undulator before inserting a new one):
a. After moving this one undulator IN, record the kick and quad
translation(s) required to correct it (1 Hz until orbit fixed). [0.2
hr/segment]
b. Measure the 1st field integrals of each undulator from 5 mm to +5 mm
using the x-slider (use new Field Integral GUI). [0.2 hr/segment]
c. Record spontaneous radiation on YAGXRAY for each individual
undulator (still only one inserted at a time), and using the Nickel foil to
narrow the spot size, especially noting any significant pointing errors
(needs 13.68 GeV). [1 hr/segment, but first one takes 1 shift?]
11. With all undulators OUT (+80 mm), increase laser-heater IR energy to EIR = 200
J, then verify IR/e spatial alignment and demonstrate YAGS2 heating effect.
Try to verify ~0.08% slice energy spread on OTRDMP at 13.6 GeV and 3 kA. [2
hrs]
12. With all undulators OUT (+80 mm), lower peak current to Ipk = 500 A using
feedback setpoint. [0.2 hr]
13. With E = 13.64 GeV, Ipk = 500 A and EIR = 200 J, and while observing
YAGXRAY, begin inserting one undulator at a time, starting from the most
upstream slot (#13). Proceed until all 21 undulators are inserted (#13 - #23).
Correct the orbit for each insertion (use steering GUI but make sure it moves the
right quad) and record all changes. [1 hr]
14. Still with EIR = 200 J, and while observing YAGXRAY, undulator orbit, and the
dump screen, slowly raise the peak current toward 3 kA (in 250-A steps). Stop if
any sign of FEL damage on YAGXRAY is apparent (unlikely at 13.6 GeV). If
any damage (determined by Stefan Moeller), inform RP and begin B4C testing
(requires vent of ST0 area). [2 hrs]
15. When ready for potentially more (any?) FEL power, and while still observing
YAGXRAY and the dump screen, lower the laser heater IR energy from 200 J
down to 10 J in 20-50 J steps. Stop if any sign of FEL damage on YAGXRAY
is apparent (unlikely at 13.6 GeV).
If any damage (determined by Stefan
Moeller), inform RP and begin B4C testing (requires vent of ST0 area). [2 hrs]
16. If no FEL light observed, or if we simply want to try and raise the FEL power, rerun BBA with all 21 undulators inserted and correct as needed (run BBA at Ipk =
500 A and EIR = 200 J). Record quad position and BPM offset changes. [4 hrs]
17. If BBA was run again (above), re-run the BFW alignment with 21 undulators
inserted and correct as needed (do at Ipk = 500 A and EIR = 200 J). Record BFW
girder position changes. [4 hrs]
18. If FEL power observed, measure FEL gain, mostly to test new Gain-Length GUI.
[8 hrs]
19. If FEL power observed, measure K for each pair of undulators using Ni foil. [>3
shifts]
20. If no FEL light observed, or if we simply want to try and raise the FEL power,
reduce energy to 7 GeV and repeat steps above (with all 21 segments inserted).
Damage to YAGXRAY is more likely with lower electron beam energy. [8 hrs]
21. Repeat at 4.3 GeV if still no FEL beam. Damage to YAGXRAY is more likely
with lower electron beam energy. [8 hrs]
22. Move on to B4C stopper test (first informing RP) after any apparent YAG screen
damage.
http://www-ssrl.slac.stanford.edu/lcls/commissioning/documents/b4ctestplan_part1_mar20.doc
23. When approved and ready, open ST1 & ST2 stoppers and take FEL x-ray through
FEE and onto direct imager. [see separate plan]
24. Go to Goose.
http://www.dutchgoose.net/Home.html