Difference between revisions of "Tuesday, Apr. 19: SWING Shift"
From Hall A Wiki
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− | ==== | + | ==== Moller Measurement ==== |
− | 5pass beam with | + | 5pass beam |
+ | |||
+ | |||
+ | |||
+ | |||
+ | ==== special Runs ==== | ||
+ | * 1/ C-hole target with VDC on | ||
+ | - 30min measurement | ||
+ | - Raster (2x3) is on | ||
+ | - 20uA up to (25uA) whichever beam is stable | ||
+ | - set LHRS p0= 1GeV/c, RHRS no change | ||
+ | |||
+ | * 2/ Multi-foil target | ||
+ | - 15min measurement | ||
+ | - Raster OFF | ||
+ | - 20uA up to (25uA) whichever beam is stable | ||
+ | - set LHRS p0= 3.36GeV/c, RHRS no change | ||
+ | |||
+ | * 3/ Julie will perform a deadtime study w.r.t prescale factor change (1hr) | ||
+ | - start 5-7AM | ||
+ | |||
+ | |||
+ | |||
Revision as of 16:52, 19 April 2016
Return to List of Daily Run Plans
Contents
Shift Duties
- Take Production data
- If Beam has been down for longer than 3 hours:
- Perform Reestablish Beam Procedure
Moller Measurement
5pass beam
special Runs
- 1/ C-hole target with VDC on
- 30min measurement - Raster (2x3) is on - 20uA up to (25uA) whichever beam is stable - set LHRS p0= 1GeV/c, RHRS no change
- 2/ Multi-foil target
- 15min measurement - Raster OFF - 20uA up to (25uA) whichever beam is stable - set LHRS p0= 3.36GeV/c, RHRS no change
- 3/ Julie will perform a deadtime study w.r.t prescale factor change (1hr)
- start 5-7AM
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 (2x2mm2) [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 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.