PREX2RunPlan2019

PREX Main

PREX Run Plan for   Commissioning   and   Auxiliary Measurements

See also the Daily Run Plan and Earlier Daily 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 checkout

1. Basic beam setup:
   • Establish low-current beam with spectrometer magnets on, verify raster. Calibrate BPM positions.
   1. MCC 1 shift Yves Roblin, Ciprian G
      1. beam transport through Compton chicane @5uA (rates in finger scintillators no more 2x halog)
      2. spot size at target (harps)
      3. turn on septum and verify still on dump (viewer available?!); clean transport to dump for PREX set points
      4. 1 arm running (Q1 on) test to see beam motion (Yves and Ciprian)
   2. Hall 0.5 shift: Ciprian G
      1. harp scans for BPM calibrations and raster check Plan Needed
      2. Bullseye scan
      3. low current beam monitoring (cavities)
2. Warm target position 0.5 shift Silviu
   • Verify target alignment, change encoder set points if needed. After this, warm targets can be used.
   1. use spot++ to find carbon hole
   2. Put in Ta or this-C target. Scan few mm up-down, left-right, verify from rates we're not hitting a frame. REMOVE?!
      1. first check of SAMs at low current
3. Cold target position 0.5 shift Silviu
   • Verify target alignment, change encoder set points if needed. After this, cold targets can be used.
   1. use spot++ to find carbon hole
4. MCC ion chamber calibration 0.5 shift Ciprian G
   • will enable us to run higher current. Procedure discussed with Eric Forman: thick target calibration procedure (ramp 2-20uA) for ALL ion chambers (including the dump); thin target: ramp 2-10uA on thin C (0.5mm).
5. Collimator checkout 0.5 shift Ye T, Ciprian G:
   1. check rates with SAMs
   2. moderate CW and thick C/Ta target so we can check temps (need a simulation for collimator power for C/Ta target)

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
   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:
   1. spectrometer momentum scan
5. Water cell pointing 1 shift Chandan G, Ryan R:
   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. Pb target, raster on: Ion chamber calibration (near target): Ciprian Gmore details needed
   2. 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

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?)

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