[Halld] Update on commissioning

[Alexandre Deur]

Dear collaborators,

This week, Hall D has seen its first beam since Fall. However, due to problems in the accelerator, the beam was not usable and we have not started yet with the commissioning. The problems that accelerator is having make difficult the simultaneous delivery of beam with maximum energy to Hall A & D. The main problems are 1) a 30s noise on energy that is likely to cause the BLM trips that have impaired delivery, 2) the RF separation is still delicate to do and may need further commissioning, and 3) one of the injector lasers is producing a beam with a significant tail. 

There was some discussions this morning with a plan that, if these problems are not partly overcome today, Hall D would be put aside for the weekend and accelerator would deliver beam to Halls A and B only. So far however, accelerator has managed to reach an apparently good beam tune to Hall D, and they seems to have reduced the problem of the 30s noise. They are presently tuning Hall A.  Thus, we may get some usable beam this week end, maybe as soon as tonight.

If we do get beam this week end, the plan is to re-establish the photon beam and then check-out all the sub-systems. 

David Lawrence will take over RC duty tomorrow morning until Monday evening. He will send a status update if there are new developments.

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