From PREX Wiki
CREX Main << August 2020 CREX Run Plan
- This plan is evolving as we move along
|Day, Date||Shift||Tasks (Responsible Party)||Comments/Status|
|Saturday Sept 12||Owl||Production||DONE|
|Sunday Sept 13||Owl (Adam/Tao)||Production.||(No scans done.) 39 min ABU!|
|Day (Bob/Eric)||Final Q2 measurement. Optics ||Acc mostly down; Bob took escorted access and switched to Counting Mode|
|Swing (Zeke/Pitt)||Optics ||Sanghwa for Analysis and remote assistance. Mostly completed optics.|
|Monday Sept 14||Owl (Adam/Amali)||Inelastic spectrum. Poletip study ||Chandan for Analysis and remote assistance. Finished optics, inelastic spectrum, poletip study|
|Day (Thia/Bob)||10am - noon Beam studies 1: Hall in Controlled Access (CA) - Install blind At PMT, Blind main Detector; noon - 4:15pm Beam available to ready Halls - we take data with blinded tubes.||Devi required for tube blinding|
|Swing (Weibin/Eric, Devi on-call)||4:15pm - 8:15pm Beam studies 2: Hall in CA - restore US PMTs, Compton e-Det work; 8:15pm - 9:15pm Beam recovery and onward delivery. Production.|
|Tuesday Sept 15||Owl (Adam/Amali)||Pedestal Scans, PITA scan. Production.|
|Day (Rom/Eric)||SAD Safety Meeting 9-11am https://primetime.bluejeans.com/a2m/live-event/tkcbphay ; Production if beam available||7:45am South Linac down, cold box trip in CHL1, recovery 10.5 hours|
|Wednesday Sept 16||Owl (Bishnu/Victoria)||Production|
|Day (Simona/Eric/B.Yale - standby)||8am start Moller measurement. Sign check. Followed by raster and Target study||Cameron supporting the raster study remotely|
|Swing (Devi/?)||Complete raster and target study. Pedestal scans, PITA scan. Production|
|Thursday Sept 17||Owl (Victoria/Siyu)||Production.|
|Friday Sept 18||Owl (Victoria/Siyu)||6am SHUTDOWN|
Optics and Q2
- Q2 measurement (Done)
- Repeat of Q2 measurement, with improved pedestal noise control.
- Detector counting mode.
- S0 trigger
- production raster and beam position
- Optics Data (Done)
- 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
- Energy Measurement (Done)
- Doug did a parasitic energy measurement Sun, Sep 13 at 20:24 .
- Blinded At PMTs (Done)
- Longish access to setup and back out, but short data taking period (production conditions).
- Reconfigure AT PMTs 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 PMTs 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).
- Blinded Main detector? (Done)
- 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.
- Inelastic spectrum scan (Done)
- 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. Use LHRS only.
- should scale all spectrometer magnets (including septum)
- Pole tip re-scattering (Done)
- 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).
- 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.
- Linearity LED tests
- This will be studied post run, during SAD
- detector crew were left off the SAD access list - Kent has repeated the request.
- Sign check
- perform at next Moller polarimeter measurement
- run Moller, Compton, and parity DAQ for quick PITA scan
- Target/Raster study
- Set up for normal production mode. Call in experts (Bob M in person, Cameron remote).
- With each raster change we start with a brief C12 run for safety, then do a brief Ca48 run.
- Raster Scan Run Plan
- One more measurement
- Spectrum run
- Laser polarization changes
- linearity studies During SAD