Next Meeting
Agenda for Next Meeting
Item Person Responsible Time ---- ------------------ -------- Progress Report on Commissioning Legg/Bohn 10 min Discussions of Lessons Learned Bohn/All 30 min Punch List for January Setup Bohn/All 10 min New Issues All 5 min Agenda for next week All 5 min
This Week's Attendees
J. Bennett, G. Biallas, C. Bohn, D. Douglas, A. Grippo, A. Hofler, K. Jordan, R. Li, P. Piot, J. Preble, Q.-S. Shu
Closed Action Items
The following actions from last meeting's report were closed out:
Items of Discussion
We now have software in the FEL Control Room for recording shift summaries, and henceforth crews are asked to prepare a summary at the end of their shifts. This process began last night. A. Hofler suggested that we use the shift logs at daily FEL meetings in parallel with what is done for CEBAF. The Commissioning Coordinator (CC) received the suggestion well and will consider doing so once we turn back on in late January to start going after first light.
Commissioning status is that we locked up yesterday at 1430, not surprisingly went through a few hiccups in the process of turning on the injector, and by 0800 had beam at the viewer immediately preceding the cryomodule after running it through the injection line with both cavities crested. Beamline parameters from the November runs seemed to work well, indicating consistent machine performance.
This morning, checkout of the vacuum-interlock system through the cryomodule down to the straight-ahead dump is proceeding. Open questions at this writing (1100 Friday) include whether to reset the vacuum-valve trip limits in the vicinity of the optical cavity, and if so, to what values, and how to configure software controlling the rf interlock to the drive laser so it does not needlessly shut down. Both are being worked this morning.
Plans are to take beam through the cryomodule today and do transient phasing tonight. Then tomorrow we take beam through the optical chicane and crest the cryomodule cavities. D. Douglas suggested we consider taking the beam all the way to the straight-ahead-dump viewer and then crest, a process that he thought would be straightforward based on experience with CEBAF. We will consider this idea.
J. Preble reported that the cryomodule's performance after thermal cycling for replacement of the troublesome valves appears unchanged. Gradients for all of the cavities are consistent with earlier measurements, as are the unloaded Q's of the entrance and exit cavities. On the other hand, the static heat load rose, raising the error bars in the Q measurements. The source of the increased heat load is not yet identified. Bottom line is that all indications are that we still have a 47 MV cryomodule.
D. Douglas gave an overview and demonstration of his Excel version of DIMAD. It is comparable in structure and capability to the FEL model server developed by the Software Group, but it runs slower. (Incidentally, P. Piot reported that the FEL model server is up and running.) The essential advantages of Dave's code is that it is implemented on a well-known user interface, and it is conveniently transportable. Other interfaces that would perhaps be better adapted to this application are mathematics packages like MathCad and Mathematica. Dave will probably spend a bit of time looking at possibilities like these. Bottom line here is that Dave is now well prepared to sit shifts, a resource we look forward to using come January turn-on!
CC advised the Commissioning Team to have a great holiday season after getting beam to the straight-ahead dump. He would like to achieve a stable profile on the dump viewer and be able to shut down a day early, mainly as a Christmas present for Deputy CC (who can then finalize the CW Setup Procedure by 24 Dec 97 as indicated below!!).
New Issues
New Action Items
Old Action Items
Procedures in Work
First Light Setup