Thursday, Apr. 7: DAY Shift

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Shift Status Notice

Chance of CW beam during this shift: shift is on stand-by

• TO must report to shift.
• Remaining crew must stay in the area.
  • Notify RC of contact information.
  • Be ready to return to shift on short notice.

Shift Duties When No Beam

• Monitor target (keep in HOME position)
• Respond to calls and alert RC as needed.
• Fill out shift checklist during this shift.
• If beam is close to returning, notify the RC.

If Beam Returns

• Perform Beam After Extended Downtime procedure from below
• Perform extended ~20 minute Carbon Hole run (only once)
• Proceed with Production data taking.

Beam After Extended Downtime

This procedure is to be

• 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.

Extended Carbon Hole Run

This is to be performed only once and may be skipped if already performed in previous shift.

• Move target to 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 the Right-HRS VDC HV OFF
  • Turn the Left-HRS VDC HV ON
  • Turn DVCS Calo HC OFF
  • Ensure 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
  • Take ~20 minute run with this setting.

Production Running

For the remainder of the shift take 1 hour runs in the production configuration DVCS: Kin_48_2

- 15uA

- LH2 target

- DVCS ON

- Calo_theta= 10.1(deg), Distance = 2.5m (from target)

- LHRS=3.996 GeV/c (negative pol), angle=20.243(deg), Q1=1916.640  (Q1 regul.OFF)

- RHRS=2.101 GeV/c (negative pol), angle=48.892(deg)

- PreScaleR : PS1=PS2=PS3=1, && PS8=200

- PreScaleL : PS9 =1, + DVCS config.


- Raster : 2x2mm^2