Template:ShortTermSchedule-RGE

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Run Coordinator: Stepan Stepanyan (757) 575-7540

PDL: Nathan Baltzell (757) 876-1789, Office: x5902

Daily RC Meetings at 13:00 in CH Room 200C, and on ZOOM: URL Link (Meeting ID: 1602110826; Passcode: 650675), except on Wednesdays, which is on ZOOM ONLY @ 15:30.

Important Notes

  • In case of medical or fire emergency, call 9-911 from a LANDLINE phone in the Counting House and inform the Crew Chief and RC.
  • In case of evacuation of the Counting Room (e.g., due to a fire alarm), grab the shift expert phone and leave the room through the "EXIT" door leading to the parking lot. Do not leave through the hallway! Call the RC once outside so the latter will call MCC to turn the beam OFF to Hall B and inform other Hall B staff members.
  • If you have symptoms or a positive COVID test, do NOT come to your shift - instead, inform the PDL and the RC and JLab medical services immediately to arrange replacements.

Tuesday, April 2

  • When the beam is back, start with beam tuning in the tagger dump:
    • ask MCC to energize the tagger magnet,
    • mask halo counters and BOM in FSD, and move the collimator to the "Blank" position,
    • in the meantime, call Eugene (beamline) to energize the solenoid and torus (if they are not energized),
    • ask for a 5 nA beam to the tagger dump, rates on upstream halo counters should be ~<1 kHz,
    • perform harp scans, 2C21 first, then the tagger_harp, and compare results with nominals (links are ported on the right side of this page).
    • If the beam profile and the position (standard deviation and the mean values of the Gaussian fits) are close to the previous tune, ask to take the beam away to prepare for the Moller run. Otherwise, work with MCC OPS to correct beam profiles and positions.
  • Preparing for the Moller run:
    • take the beam away, open the Moller GUI, and follow instructions to configure the Moller polarimeter,
    • when ready, ask for a 20 nA beam and start the run. Make sure the ACC/Coinc ratio is <0.1, and the charge asymmetry is <0.2%
    • repeat the Moller run with with revered Helmholtz field.
  • After Moller runs are complete:
    • ask MCC to degauss the tagger magnet.
    • move the collimator to the 20 mm position. Unmask all halo counters and BOM in FSD.
    • ask MCC to send a 5 nA beam to the Faraday cup when ready.
    • Remind MCC about our BPM positions; see the right side of this page. Ensure the upstream and midstream halo counter rates are ~<10s Hz.
    • set the FSD to harp scan mode - trip limits 1 MHz, dwell time 50 ms, and perform 2H01 harp scan with 5 nA beam,
    • compare it with the nominal pone posted on this page. If all is well, prepare for data taking.
  • Remove the beam and start turning the detectors on. In the meantime, move the solid target to the Pb (lead) position and fill the cryo target (which may take an hour).
  • When everything is ready, ask for a 10 nA, check the rates on detectors, and if everything looks OK (compare scalers on the main GUI with before machine down rates) proceed with production data taking on LD2+Pb.

Production data taking

  • Target: Yes
  • Beam Blocker: OUT
  • Configuration: PROD67

In case of the need to manipulate the whole target system - cryotarget or solids - please contact the target experts.

LD2+Pb runs

  • Trigger: rge_inb_v1.0_200MeV.trg
  • Beam Current: 70 nA
  • Use PROD67 configuration (this will not PIN data)
  • 3-hour runs

For information on triggers, please see here: https://logbooks.jlab.org/entry/4267187


References

BPM Positions

BPM X (mm) Y (mm)
2C21A -0.4 +0.7
2C24A -1.7 +0.5
2H01 -1.0 +0.25

Harp Scans

FSD Thresholds

Do NOT change FSD settings without approval from RC or beamline expert!

  • Upstream: 2 kHz
  • Midstream: 2 kHz
  • Downstream: 100 kHz
  • BOM: 50 kHz
  • 5 ms dwell time

Charge Asymmetry

General Reminders

  • The main lights in the Hall and the Forward Carriage lights must be kept off during data taking.
- Refer to these reference photos, ON and OFF
- The main, dome lights can be turned off without entering the Hall.
  • Beamline
- Do not run over 30 minutes above 90 nA with a 5-pass beam without the beam blocker IN.
- If there is any concern about beam stability, ask MCC if orbit locks are on (they should be).
- Document any beam condition change and send scaler GUIs to HBLOG.
- If HWP is changed, start a new run.
  • During beam tuning and Møller runs
- DC: HV OFF
- SVT: LV ON, HV OFF
- MVT: LV ON, HV ON in SAFE Mode
  • To access the Hall
- If you need to enter Hall B, alert Denny Insley (757-897-9060, cell/text: 757-810-9576) and the Run Coordinator.
- Check in with the shift personnel before entering the hall.

DAQ Operation

  • Standard end and start of a run
    1. End run
    2. Abort
    3. Download
    4. Prestart
    5. "Go"
  • Restart DAQ from scratch
    • e.g., when changing configuration or trigger files, when the run did not end correctly, or after ROCs are rebooted
    1. Cancel
    2. Reset
    3. Configure
    4. Download
    5. Prestart
    6. Go