[Halld] Spring 2018 run status

[Alexandre Deur]

Dear Collaborators,

At today's MCC 1:30 meeting, Halls A, B and C indicated their desired number of passes and that they will ask for several pass changes. Some of those will occur within the first week after the start of the spring 2018 run. Given that the 2-pass and 4-pass separators still have issues, a run schedule that allows the four halls to run concurrently is being worked out. This is relevant to Hall D since for 4 halls operation, Hall D must share a slit with one of the other hall, preferably A or B (C will run the highest current, which makes sharing with D more difficult). The hall with which Hall D shares a slit must be at 5-pass for the beam separation to be possible. It seems that for the first few days, we will be sharing with Hall A (again, the schedule is still being worked out, so that might change). This means that our maximum current will not be constrained, but that we may experience a larger bleedthrough. This one should no larger than about 5 nA. Later we will share with Hall B, with the constraint that our current has to be within roughly a factor 5 of the Hall B current. 

For information, the currents for standard production runs are (for Spring 2018): 

20 uA in Hall A;
70 nA in Hall B;
65 uA in Hall C;
150-200 nA in Hall D.

Jefferson Lab will be closed tomorrow (Thursday 4th) due to the upcoming snowstorm. Consequently, there will be not much progress between now and Friday morning to discuss, so the coordination meeting of Friday 5th is cancelled.

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