Thursday, Apr. 14: SWINGShift
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Contents
Shift Duties
- Take Production data
- If Beam has been down for longer than 3 hours:
- Perform Reestablish Beam Procedure
Completed works
1/ MCC beam study (8:00AM-2:00PM)
2/ During this time,
a) Radcon access to Hall for replacing Hall-A Dump diffuser Interlock VME card with new firmware (ion chamber check) ELOG:3398771 b) MCC will check FFB in the SL (2L26 region) ELOG:3398780
Ongoing
3/ Establishing beam Compton chicane (Jay+Cip + Juan Carlos are aware of this !)
parity check ?
=
SINCE 5TH PASS RF SEPARATOR FAILED: WE DECIDE TO POSTPONE THE COMPTON NEXT MONDAY, LASER IS OFF
==
Production Running
For the remainder of the shift take 1 hour runs in the production configuration DVCS: Kin_48_4
Beam current | 15 μA |
Beam Energy | 11 GeV |
Target | LH2 |
Raster | ON (2x3mm2) [height x width] |
VDC HV (both arms) | ON |
DVCS Calo HV | ON |
DVCS Calo Angle; | 10.069° |
DVCS Calo Distance | 2.5 m |
LHRS Polarity | Negative |
LHRS Momentum | 3.360 GeV/c |
LHRS Angle | 24.925° |
LHRS Q1 Current | 1916.640 (regulator OFF) |
LHRS DAQ Config | DVCS |
prescaleL | PS9=1 (all others zero) |
RHRS Polarity | Negative |
RHRS Momentum | 2.204 GeV/c |
RHRS Angle | 48.75° |
RHRS DAQ Config | RHRSadaq2 |
prescaleR | PS1=PS2=PS3=1, && PS8=200 (all others zero) |
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
- 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.