CREXAuxiliaryMeasurements-Aug2020

CREX Main << August 2020 CREX Run Plan

Schedule

• 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
Sunday Sept 13	Owl (Adam/Tao)	Pedestal Scans, PITA Scan. Production.
	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; noon - 4:15pm Beam available to ready Halls; 4:15pm - 9:15pm Beam studies 2; 9:15pm Beam recovery and delivery. Install Blind At detector (parasitic).	Devi required for tube blinding
	Swing (Devi/Eric)	Recover from Beam Studies. Production (with Blind Quartz dets in place from now on).
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.

Backgrounds

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).

Detectors

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.

Other

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