[Halld] Saturday's RC meeting cancelled. Short update

[Alexandre Deur]

Dear collaborators,

We did not get beam since yesterday's 9am. Consequently, today's (Saturday 27th) Run Coordination meeting tomorrow  is cancelled.

Since the shut down of the accelerator on Wednesday at 3:25pm, we got only a little amount of usable beam: about 6h. The only notable progress is the completion of the first step the TAC trigger set-up and more development on the main trigger. Problems with unstable Hall D orbit, a mis-behaving C100 cavity account for the difficulties in getting beam. In addition, a pass change (1 pass to 4 pass) for Hall A started at 9am Friday, followed at 3pm by bringing up Hall B reduced further our possibilities of beam time yesterday. Hall B was successfully brought up and took a bit of beam last night. The 4 pass to Hall A is done but the separation with Hall D is not finished yet. Optics matching is also needed. So there is no prospect of beam for Hall D/A until several hours, if everything goes smoothly. 

Once the C100 cavity trips are resolved, Hall B will be applying its prerogative as the priority hall and demands that other hall activities that would disrupt B beam delivery to be suspended for 2h. This is not too bad for us since Hall A is in controlled access and the tune to Hall D can then be done mostly parasitically to Hall B delivery (or so it is claimed).

Thank you,
 
Alexandre Deur, Hall D Run Coordinator.
 
RC cell: 757-383-5542
Office Phone: 757-269-7526