Wednesday, Apr. 20: DAY Shift
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- Take Production data
- If Beam has been down for longer than 3 hours:
- Perform Reestablish Beam Procedure
CHANGE OVER KINEMATICS
- Remember, we will have a controlled access and 10 limited keys !!!
- 1/ Call controlled access 7:00AM and radiation survey by RadCon Group
- 2/ Calo. position/angle survey 8:00AM
I spoke to Chris Curties in this morning for Calo. position survey. I am not sure if he needs a restricted or controlled. He will back to me with detail schedule later. GMp needs a detector position survey after the end run. Jack is working on LHRS magnets
- Once survey is done, configuration change will be followed.
- 3/ Detector
GMp will change the LHRS angle 43deg (RHRS no change) DVCS Calo. will be removed. / secure safe place (Temp.Location: near DVCS HV crate area till end run / After end run, move into left side of RHRS)
- 4/ Beam
4hrs beam setup after 16:00 / change RF freq. from 250MHz to 499MHz 4Pass beam for GMp experiment (one pass setup till end run) MCC will definitely try high current up to 60uA. The BCM and mini-target boiling tests will be carried out.
Reestablish Beam Procedure
This procedure is to be run every time we recover from an extended beam down (>3 hours).
- Harp Scans
- Move target to HOME position (if not already there) (mask target motion!)
- Turn VDC HV OFF for both arms.
- Turn DVCS Calo HV OFF
- Ask MCC for Raster OFF (check that it turns off in the scope)
- Ask MCC to perform Harp Scans (on IHA1H04A and IHA1H04B)
- Must have three peaks on each with a resolution of ~200-500 μm
- Have seen a "shoulder" on the last peak before. May be acceptable if other 2 peaks are fine.
- Ask MCC to make an ELOG with the results of the Harp Scans
- Beam Centering on Carbon Hole Target
- Move target to the Carbon Hole position (mask target motion!)
- Ensure Left-HRS momentum is ~1 GeV/c
- Set Left-HRS DAQ configuration to LeftHRSnew
- Set prescales as ps_i = 1 for i = 1-6, and ps=0 for all others
- Turn VDC HC OFF for both arms.
- Turn DVCS Calo HV OFF
- Ask MCC for Raster ON at 2x2 or whatever is on the whiteboard
- Check that it turns on in the scope, and check Raster GUI to confirm 2x2 setting
- Ask MCC for 5 μA beam
- Run spot_L as explained in the detailed instructions
- If not centered ask MCC to move beam accordingly (check board for coordinates)
- Repeat test with different beam position until target is centered.
- Raster Target
- Start the same settings as carbon hole centering
- Move to Raster Target (mask target motion!)
- Ask MCC for 5uA beam with Raster ON (2x2)
- Check rates and confirm they are consistent with rates seen during HOME position
- If the rates are low and consistent, then move on to next step
- If the rates are high, it may indicate the beam has an angle that causes the beam to scrape on an edge of the target
- Notify the RC
- Ask MCC to readjust BPM positions until this angle is removed
- When done, perform another Carbon Hole run just to be sure.