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Revision as of 07:04, 13 September 2020 by Covrig (Talk | contribs) (Schedule)

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CREX Main << August 2020 CREX Run Plan


  • This is just a proposal, not settled.
Day, Date Shift Tasks (Responsible Party) Comments/Status
Saturday Sept 12 Owl Production DONE
Day Production DONE
Swing (Zeke/Pitt) Production DONE
Sunday Sept 13 Owl (Adam/Tao) Pedestal Scans, PITA Scan. Production. No scans done, 39 min ABU!
Day (Bob/Eric) Final Q2 measurement. Optics ARM support for access to the huts to go do counting mode
Swing (Zeke/Pitt) Optics Sanghwa(?, or Cip) for Analysis and remote assistance.
Monday Sept 14 Owl (Adam/Amali) Inelastic spectrum. Poletip study (if time remains). (Ask Chandan for remote help).
Day (Thia/Bob) 10am - noon Beam studies 1 (Install blind At PMT); noon - 4:15pm Beam available to ready Halls - we take data. Devi required for tube blinding
Swing (Devi/Eric) 4:15pm - 9:15pm Beam studies 2 (Remove blind At PMT); 9:15pm Beam recovery and delivery. Production.
Tuesday Sept 15 Owl (Adam/Amali) Production (Maybe also pedestal scan?)
Day (Simona/Eric/Rom) 8am start Moller measurement. Sign check. SAD Safety Meeting 9-11am. Blind main detectors heading into this. Need RadCon support for blinding immediately after safety meeting
Swing (Devi/Siyu) 1. finish Moller measurement. 2. blind detector measurement. 3. unblind main tube. 4. Back to production Need RadCon support for unblinding, in mid-to-late swing. Need an additional access for counting mode config.
Wednesday Sept 16 Owl (Bishnu/Victoria) Production
Day (B.Yale/Siyu) Followed by raster and Target study
Swing (Devi/Eric) Complete raster and target study. Production
Thursday Sept 17 Owl (Victoria/Siyu) Production
Day (Rom/Weibin) SHUTDOWN
Swing (Zeke/Adam) -----
Friday Sept 18 Owl (Victoria/Siyu) -----
Day (Rom/Weibin) -----

Optics and Q2

  1. Q2 measurement
    • Repeat of Q2 measurement, with improved pedestal noise control.
    • Detector counting mode.
    • S0 trigger
    • production raster and beam position
  2. Optics Data
    • Sieve IN, dp=+1, 0, (maybe -1). Raster/no raster thin C, raster H20
    • Priority is 1 dp change (both arms!) plus backout, and 10 runs. Watercell runs should be long.
    • Assume 3 hours for magnet changes and 2 hours for data taking. ~ 1 shift
    • See grid on optics data spreadsheet
  3. Energy Measurement
    • I think this is complete. I need to check with Doug.


  1. Blinded At Quartz
    • Longish access to setup and back out, but short data taking period (production conditions).
    • Reconfigure AT detectors to use blinding cap, attach to US PMTs.
    • This will be done during the long beam studies break on Monday
    • software blinding on the AT tubes must be disabled
    • Check pedestal noise in counting and in integrating mode. We need low noise is the blinded tube, and we can't add noise to our main detector!
    • Integrating measurement for asymmetry measurement
    • (Do we want counting mode measurement for rate in blinded At tube?)
    • (yield only normalizable using table-gain gain curves).
  2. Blinded Main detector?
    • Need 2 hours to blind main detectors. Then another hour after meaurement to unblind.
    • short-ish yield runs in integrating mode.
      • Software blinding must be disabled on the blinded MD tubes for this study
    • short counting mode run to get relative rate
    • Then return. Keep AT blinded piggybacked for asymmetry measurement.
  3. Inelastic spectrum scan (~1 shift)
    • Needs a detailed run plan
    • Counting mode. Current 0.5uA or so? Turn quartz HV off.
    • Measure dp spectrum form dp=nominal to dp=-25%, in 5% steps.
    • should scale all spectrometer magnets (including septum)
    • Once the elastic peak is out of the focal plane, it may be possible turn on the S3 and S0 scintillator. This should be done when possible, and the T1/T2/T3 trigger rate recorded for each run.
  4. Pole tip re-scattering
    • Counting mode (VDC tracking). Counting mode on detector is ok (and helpful) but not needed.
    • Q3 turned off.
    • Run three septum setpoints: nominal, -5%, and +5%. Need ~1M S0 trigger events per run (and more is better).


  1. Linearity Studies (PITA + current scans)
    • These are ongoing - should continue regularly. At least once more,maybe twice.
    • Useful to have one after we get the blinded tubes in place.
    • Current scans for detector and BCM pedestals. Skip the BPMs, I think.
  2. Linearity LED tests
    • This will be studied post run, during SAD
    • detector crew were left off the SAD access list - Kent needs to get this fixed.


  1. Sign check
    • perform at next Moller polarimeter measurement
    • run Moller, Compton, and parity DAQ for quick PITA scan
  2. Target/Raster study

Moller polarimetry

  1. One more measurement

Compton polarimetry

  1. Flip DOCP???
  2. No-target runs
  3. Laser polarization optimization
  4. Laser polarization flip
  5. linearity studies