RC meeting and Run Plan, Thursday Oct. 11
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- Beam quality First 20.5 hours Last 3.5 hours
- Bottom line: terrible first ~19 hours, situation improved markedly in the last ~5 hours
- Current fluctuating between 40uA and 50uA
- Progress
- Added 23% of the minimum statistics on LH2 for the current run
- Completed dummy for the current kinematic point
Requiring attention
- HMS Dipole LN2 fill level very high (essentially full) [1]
- Not urgent, small ice ball forming in non-critical location (we're watching it)
- Cause: seems like JT-4 is stuck again
- Will coordinate with Andy Kenyon early next week for opportunistic escorted access
- Alarm disabled for now, re-enable when fixed. Instructions: [2]
- Rotation to small angle: Complications when going to 6.50 deg tonight:
- Risk tripping the rotation alarm: Holly on standby
- Need new limits on ion chamber diffusors if we run above >=50uA (Jay Benesh confirmed this is the case), more info here: [3].
- SHMS rates expected to be close to detector limit (tracking efficiency), might need to limit beam current.
- Would take care of above issue. Current estimate from Garth puts us at <55uA.
Other requests (non-urgent)
- RadCon wants to put a small detector in the SHMS hut during the next opportunity
- Needs few hours, communicate with Brad when next opportunity arrises
- Hall D needs opportunistic 1shift of HallC down for beam studies, not pressing right now (needs to be done before end-of-run)
- Unlikely this will happen in the next week
Plans - Physics
- Continue until ~midnight with Q2=3. W=3.14 x=0.25 theta_Shms=9.42, hopefully will reach 50-60% of statistics goal
- Change SHMS angle to 6.50 deg (close to software minimum) for next kinematic point.
- Aim for 55% of minimum statistics (same as 12 degree point)
- Expect to stay there for ~5-7 shifts.