Difference between revisions of "PREX2RunPlan2019"

Revision as of 23:30, 16 June 2019

PREX Main

PREX Run Plan for   Commissioning   and   Auxiliary Measurements

See also the Daily Run Plan and Earlier Daily Run Plan

PREX I - 2010 Run Plan

The experiment is approved for 35 PAC days including 25 production days. There are 49 days on our calendar.

Below is a list of tasks in the approximate time order, with person(s) responsible, approximate amount of time required, and comments about the conditions or needs. The time will, in most cases, be broken up into manageable chunks. For example, the GEM commissioning will occur in about 4 periods of time, each 4 hours, separated by at least one day. After commissioning we go into a regular production mode; we will provide an updated document webpage for shift worker instructions.

Total time: ?   Based on this list, each day we will come up with an adjustment to the Daily Run Plan. Some flexibility will be needed to accomodate problems and changes in plans.

Beam Restoration

1. Basic beam setup 1 shift: Yves Roblin
   • establish tune beam and low current CW beam in the hall.
   1. Establish beam to dump, through Compton chicane
   2. Design match to hall expected as part of original configuration, if additional beam time is required will be necessary to coordinate with optics/production runplan
   3. ion chamber calibration will be skipped until we can get targets in (MASK ION CHAMBERS); CG will coordinate
2. Source and Parity Quality Beam 0 shift (complete before 6/17): Caryn Palatchi, Amali Premathilake, Kent Paschke
   1. Source laser optics configuration and initial setpoints done
   2. Wein left/ Wein Right injector optics configuration done
   3. Characterize injector optics configuration in progress

Low Current Commissioning

• Basic beamline commissioning
  • Establish low-current beam with spectrometer magnets on. Establish centering on collimator. BPM offset calibration. Commission target ladders.
  • Preparations:
    • Stripchart on ion chambers, with bpm4e and bpm4a positions
    • stripchart on collimator and beamline temps with bepm 4a and 4e positions (Can we get calculations in stripcharts, like position at target and position at collimator as calculated from bpms?)
    • stripchart on compton rates (with beam current)

1. MCC 1 shift Yves Roblin, Ciprian G?
   • Tune mode. No target. Raster off. Ion chambers masked. (Requires Steve to sign off on this, I think)
   1. beam transport through Compton chicane up to 5uA CW. Rates in finger scintillators no more 2x halog
   2. spot size at target (harps) (what should this be? In PREX-1 it was typically 150-200 um in each dimesion, but I can't figure out what it finally settled on. I don't think should be smaller than 150x150um, but nominal spec is 100-300um) Can harp scans be taken with tune beam? If not, use 5uA CM, but keep eye on compton rate, ion chambers, temps.)
   3. Tune beam. Turn on septum and verify still on dump. Clean transport to dump for PREX set points
   4. 1 arm running (Q1 on) test to verify no beam motion.
   5. Turn on both Q1 spectrometers.
2. Hall bullseye scan 0.5 shift Bob M?
   • harp scans at each of 5 points around nominal center, (0,0), (2,2), (2,-2), (-2,-2), (-2,2).
   1. Tune beam, find each point. Watch ion chamber and temperature stripcharts.
   2. If no sign of interception, use 2-5uA CW for harp scans for each position and get BPM calibrations.
      1. Watch ion chamber and temperature stripcharts.
      2. If expert is available, parasitically collect data for low current beam monitoring (cavities)
   3. position at (0,0). Set nominal raster to 8x8. Establish 2uA CW. Watch ion chamber and temperature stripcharts. This should verify passage through collimator. If IC or temp jump, terminate beam, try with 6x6 or 4x4 raster. If cannot pass, go to collimator position scan.
3. Warm target position 0.25 shift (Silviu?)
   • Verify target alignment.
   1. insert warm ladder, carbon hole.
   2. Set raster nominal 8x8 (or what could be used.)
   3. establish 2uA CW. Run spot++ to find carbon hole. log it.
   4. Adjust raster setting to establish 4x4 raster size. Log it.
   5. if carbon hole not in 4x4 raster view, need to reconsider. (move beam, or use off center?)
4. MCC ion chamber calibration - Thin target 0.25 shift
   • will enable us to run higher current. Procedure discussed with Eric Forman: thin target: ramp 2-10uA on thin C (0.5mm).
5. Cold target position 0.25 shift (Silviu?)
   • Verify target alignment.
   1. insert warm ladder, carbon hole.
   2. Set raster nominal 8x8 (or what could be used.)
   3. establish 2uA CW. Run spot++ to find carbon hole. Log it.
   4. Set raster to 4x4 set point from before. Use spot++ to verify it.
   5. if carbon hole not in 4x4 raster view, need to reconsider. (move beam, or use off center?)
   6. Move to natural lead target
   7. establish 2uA CW. Run spot++ to verify raster size, not hitting edges. Log it.
   8. set raster to large nominal setting (8x8, or what can be used). re-establish 2uA CW. Use spot++ to look for edges of target.
   9. return raster to 4x4 set point. verify with spot++.
6. MCC ion chamber calibration - thick Target 0.25 shift Ciprian G, Kent P
   • Procedure discussed with Eric Forman: thick target calibration procedure (ramp 2-20uA) for ALL ion chambers (including the dump)
   • Must keep rates in compton finger scintillators no more 2x halog
   • parasitic: first check of SAMs at low current (page devi? or dustin? when starting)
7. Collimator checkout 0.5 shift Ciprian G, Kent P, Dustin M/Devi A;
   • will verify that we are cleanly going through the collimator and cross check power deposition calculations
   1. parasitic: check rates with SAMs
   2. 2uA CW and Ta target. raster "large" (8x8 or as allowed). Watch temperature and ion chamber levels.
   3. spot++ to verify not hitting target edge
   4. raster to actual 4x4 setpoints. establish 5uA CW. Watch temperature and ion chamber levels.
   5. Move beam in 1mm increments until temperature increase or IC level increases. Log changes.
   6. Center beam at mid-point between increasing temp or IC level.
   7. compare to position of carbon hole on warm and cold ladders. Do we need to change encoder positions?

Spectrometer Commissioning

Detailed Optics Plan Name and time assignments needs to be worked out by optics crew

1. tracking checkout - Tune B configuration 1 shift: Bob M, Ryan R, Chandan G
   1. Sieve IN: initial checkout
      1. put in C/Ta target; check rates with scalars
      2. VDC + GEM checkout; look at tracks, VDC spectra; (GEM):noise, pulse-heights, tracks
      3. Sieve reconstruction verification
2. Tune septum and HRS magnets - Sieve IN 1 shift Nilanga L, Chandan G, Ryan R:
   1. tune septum for the central ray (quad scans)
   2. inner edge verification
   3. Q1 acceptance scan
3. Small spot at quartz Sieve IN, thin Carbon, 0.25 shift Ryan, Dustin, Seamus or Nilanga
   1. modify tune to get small spot at quartz (with raster on)
4. Optics calibration data - Sieve IN 0.5 shift Chandan G, Ryan R, Ye:
   1. spectrometer momentum scan
5. Water cell pointing 1 shift Chandan G, Ryan R, Ye:
   1. Sieve IN: pointing measurement
   2. Sieve OUT: pointing measurement
6. Quartz detector checkout 1 shift: Dustin M,
   1. verify small spot at quartz (thin C, low current, no raster, sieve out)
   2. thin C, low current, no raster, Sieve OUT: positions Plan
   3. PMT spectra
   4. rates
   5. stub check?!
7. Q2 measurement 0.5 shift:
   1. Production target

High current checkout

1. Basic setup 0.5 shift Yves R, Ciprian G:
   1. No target: high current setup through Compton (backgrounds on fingers and Compton MD) -- try to go to 70uA (or max, no less than 40uA)
2. High current with target 0.5 shift Ciprian G, Dustin M:
   1. Detector and SAM voltages (Dustin M)
3. Beamline instrumentation calibration 0.5 shift Caryn P,
   1. Current ramp for BPM/BCM calibrations and detector pedestals
4. Initial production condition test 0.25 shift Caryn P,
   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
5. Width studies 0.5 shift KK,
   1. detector and SAM widths, targets, shutters, etc
   2. deinstall shutters at conclusion of test

Establish Production Conditions

1. Beam modulation 0.5 shift Ye T,:
   1. turn on and set amplitudes (plan needed)
   2. test orthogonality
2. Detector checkout 1 shift Dustin M:
   1. quartz detector stub test (plan needed)
   2. width study (plan needed)
   3. raster sync (plan needed)
3. Spin Dance 1 shift: Simona Malace, Sanghwa Park
   1. Moller polarimeter commissioning (establish beam) (plan needed)
   2. Short spin dance (run plan needed, established optimal spin angle for this Wien state) (plan needed)
4. Hall PQB 1 shift Caryn P,:
   1. Check asymmetries in the hall
   2. Adiabatic dampening / Matching (plan needed)
      1. Use helicity magnets to tune phase trombone
   3. Establish feedback (if Hall C is not on schedule their feedback for later)
5. Production: 0.5-3 shift? All
6. AT measurement: 1.5 shift? All (plan needed)
   1. Do we need to verify zero longitudinal using Moller polarimeter?
   2. Carbon
   3. Lead
   4. Calcium
7. Initial Moller commissioning 1 shift Simona M, Sanghwa P,
   1. minimal set for first absolute measurements
8. Initial Compton commissioning 1 shift Dave G, Juan Carlos C,
   1. minimal set for measurement conditions

Start Production

Important Activities After First Few Days

1. Linearity Studies --
2. Background Studies --
   1. Scans of Septum Magnet and HRS Dipole
   2. Thin Lead Target to check for inelastics at high-resolution
   3. Thin C12 to measure diamond background
3. Possible scan of Q1 to optimize acceptance and verify that collimator defines acceptance. (old idea, still relevant?)
4. We will start with the Wein in Spin-Right. Once we switch to Spin-Left we need to do another spin-dance.

Polarimetry Studies

1. Compton Commissioning --   Gaskell, et.al.
   1. Beam Tune, Background reduction -- Bteam,
   2. Compton Cavity Checkout --
   3. Photon Detector Checkout -- CMU group
2. Moller Commissioning -- Simona Malace, Don Jones, et.al.
   1. Magnet Alignment -- 1 shift (swing)
   2. Raster size and pulse-mode -- 1 shift (day)
   3. Target commissioning - 3 shifts
   4. Pulse-mode target commissioning - 2 shifts
   5. DAQ checkout -- 1 shift

Important Activities During run

1. Linearity Studies --
2. Background Studies --
3. Repeat Q2 and pointing measurements
4. Arc Energy Measurement