CREXRunPlan-August20

CREX Main

CREX August 2020 Run Plan for Commissioning and Auxiliary Measurements (In Development)

See also the Daily Run Plan and Previous Daily Run Plans and Fall 2020 Auxiliary Measurements

PREX I - 2010 Run Plan PREX II - 2019 Run Plan PREX2 2019 Auxiliary Measurements

Original CREX Run Plan and original CREX Auxiliary Measurements

Beam Restoration and Low Current Commissioning

1. Basic beam setup
   • establish tune beam and low current (up to 2uA?) CW beam in the hall. --Done
   1. Establish beam to dump. --Done
   2. dump ion chamber calibration? (Low current.) --Done
      • assume collimator centering as before, trajectory as before
      • spectrometer magnets on --Done
      • insert optics C-hole target, verify target location and raster calibration with Spot++ --Done
        • Presumably also need low current ion calibration for C-hole target? --Done
      • If hole is significantly different, re-verify BPM positions, log present spot++ and link comparison spot++. Call Kent (434-964-6777).
2. First Spectrometer optics / chamber calibration check
   • Carbon optics target, sieve in (verify acceptance, verify optics db with new VDC alignment/calibration). --Done
   • same, with GEM data --Done
   • Verify Cold target position
   1. spot++ on C-hole (low current IC calibration?) --Done
   2. spot++ on Ca-48 (low current IC calibration?) --Done
3. Detector alignment --Defer for later
   1. start with initial detector guess for detector alignment. (sieve out, Ca-48 target)
      • Do not refine for small details! +/- 2mm is fine)
      • Do not adjust At detector alignment at this time
   2. if right arm not functional, use GEMs with Chandan's GEM alignment?
   3. Take Q2 data (longer run after alignment selected)
4. Optics:
   1. C-foil optics data (sieve in, dp=+1,0,-1) --done dp=-1,0; defer - need dp=1 with sieve, and sieve out C-foil data
   2. water cell data (sieve in dp=+1,0,-1) --done dp=-1,0; defer - need dp=1 with sieve and sieve out watercell data
   3. Do we want:
      • repeat harp/bullseye scan? --Done
      • repeat collimator centering scan? --may be we can skip this

High current checkout

1. Establish high current to hall dump. 150uA. Radiation, IC levels should match expectation.
2. Ion Chamber calibration - thick Target 0.25 shift
   1. Should be easy/standard procedure, but verify calibration matches old calibration --Done
   2. verify trip points match old trip points, running conditions for high current match old high current running. If not, differences must be understood. --Matched pretty good
3. Setup beam through Compton chicane. --pnding
   • must keep watch on Compton rates whenever through Compton chicane --ongoing
4. FFB commissioning. Expected to be used when running high current --ongoing
5. Establish beam on cold target --Done
   • integrating mode detectors --Done
   1. C-hole, spot++
   2. Thick carbon target. Spot++ to verify on target
   3. Thick carbon to high current.
   4. Ca-48 target. Spot++ to verify on target
   5. Ca-48 to high current. Burn off (30 minutes each at 50,100,150uA) Call Silviu just before starting this
6. Verify beam modulation functionality --Done
   • low current test, then high current to watch of Ion Chamber rates or beam loss
   • Ignore orthogonality for first test
7. Test production with 1-2 hours. --Done
   1. detector and SAM widths
   2. regression sensitivities
   3. beam noise and asymmetry check
   4. collimator water and thermocouple temperatures,
   5. radiation monitors and ion chamber stability
   6. Tune beam modulation orthogonality, if needed, after 1-2 hours, then take at least 1 hour data to confirm test.

Other Early Tests and Checks (first few days)

1. Beam Monitor calibration
   • soon after restart
   1. Run current scan using Unser to calibrate beam charge monitor readout in parity DAQ.
      • Run the Compton DAQ concurrently, for calibration
   2. Go to FixedGain when at 150 uA on bpms (list of crates???) and repeat local current scan to set bpm pedestals.
2. Fine-tune detector alignment
3. At detector alignment
4. Compton commissioning
5. Moller measurement

Other Tests and Checks

1. Do we need to repeat spin-dance?
2. Linearity Studies
3. Repeat Q2 and pointing measurements
4. Arc Energy Measurement
5. Background Studies
   1. Scans of Septum Magnet and HRS Dipole
6. Possible scan of Q1 to optimize acceptance and verify that collimator defines acceptance. (old idea, still relevant?)

Polarimetry Studies

1. Compton Commissioning
   1. Beam Tune, Background reduction
   2. Compton Cavity Checkout
      1. Establish laser in cavity
      2. Move photon detector to visual center, scan beam for collisions
      3. Establish orbit lock
   3. Photon Detector Checkout
      1. Detector power-up, find optimal gain.
      2. Center detector with fingers.
      3. 15 minute spectrum and rate study.
      4. Brief target-out run? (Probably not necessary but may be desirable)
      5. Polarization commissioning run (up to 2 hour target-in)
      6. Jaws checkout (?)
2. Moller Commissioning -- Simona Malace, Don Jones, et.al.