PREX2RunPlan2019

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This is a Draft being updated from previous run plans. Please ignore until further notice

This was for the 2010 PREX-I run.   A run plan for PREX-II and C-REX is forthcoming.


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.


Beam Restoration

  1. Basic beam setup: Yves Roblin,
    • beam transport to dump
    • beam transport through Compton chicane
    • Ion chamber calibration for beam interception (on ladder); tune beam
  2. Source and Parity Quality Beam: Caryn Palatchi, Amali Premathilake, Kent Paschke
    • Source laser optics configurations in progress
    • Wein studies done


Low current checkout

  1. Basic beam setup:
    • beam transport through Compton chicane @5uA (Yves Roblin, Dave Gaskell)
    • spot size at target
    • harp scans for BPM calibrations and raster check
    • Bullseye scan
    • low current beam monitoring (cavities)
  2. Septum checkout:
    • clean transport to dump for PREX set points
    • first check of SAMs (collimator effect?!)

Spectrometer Commissioning

  1. tracking checkout:
    • Sieve In: put in C/Ta target; check rates with scalars
    • VDC checkout; look at tracks, spectra
    • GEM checkout; noise, pulse-heights, tracks
    • Tune septum and HRS magnets
  2. Quartz detector checkout:
    • rates, stub check, positions
  3. Water target:
    • Q2 measurement


High current checkout

  1. Basic setup:
    • Ion chamber calibration (near target)
    • collimator checkout (check rates with SAMs)
    • high current setup through Compton
  2. Beamline instrumentation
    • Current ramp for BPM/BCM calibrations
    • FC2 check of UNSER?!
  3. MOLLER polarimeter: Simona Malace, Sanghwa Park
    • Solenoid alignment
    • Spin dance
  4. Hall PQB:
    • Check asymmetries in the hall
    • Adiabatic dampening
      • Use helicity magnets to tune phase trombone
    • Establish feedback
  5. Beam modulation:
    • turn on and set amplitudes
    • test orthogonality
  6. Detector checkout:
    • SAM commissioning
    • stud test
    • width check
    • raster sync
  7. Production: (1 day)
  8. AT measurement: # AT measurement



Beam Restoration

  • Basic Beam Setup -- 1 shift   Yves Roblin, Bteam
    • Establish beam to dump, through compton chicane, spot size at target.
    • 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
  • Source and Parity Quality Beam -- essentially done   Caryn Palatchi, Amali Premathilake, Kent Paschke
    • Wein left/ Wein Right injector optics configuration
    • Source laser optics configuration and initial setpoints

Low Current Checkout

  • Raster check
    • Verify raster size with harp scans
  • Septum checkout (Sieve IN) -- 0.5 shift
    • Verify septum does not steer beam (clean beam to dump with energized septum)
  • Target Alignment Check (Sieve IN) -- 0.5 shift
    • Check spot with Carbon hole, lumi detectors and/or detector rates
    • Put in Ta or ultra-thin C12 target
    • Scan few mm up-down, left-right, verify from rates we're not hitting a frame.
  • Beam line alignment check (Bullseye scan) -- 0.5 shift


Spectrometer commissioning and Optics calibration

  • Establish low current (1-2 uA) beam, verify beam monitoring.
    • Verify beam monitoring in BCM, striplines
    • Verify beam monitoring in low-current cavity triplets
  • VDC Checkout --   Dustin McNulty, Bob Michaels
    • put in C or Ta target. Look for sieve holes; first check on optics
  • Quartz detectors checkout --   Dustin McNulty
    • Calibrate detector x-y movers in VDC coordinates
  • GEM checkout --   Nilanga Liyanage
    • First look at noise, pulse-heights, tracks
  • Spectrometer checkout (Sieve OUT) -- 1 shift
    • Low-current cavities (Priority activity) --   John Musson
      • Need before subsequent program, especially Optics and Q2
    • VDC Checkout --   Dustin McNulty, Bob Michaels
      • First spectra on specific thin targets
      • Learn to measure rates to 10% and study rate dependence effects
    • Quartz detectors checkout --   Dustin McNulty
      • Detector pulse height spectra
      • If possible, compare 6 and 10 mm blocks
      • Map shadow of quartz (both primary and A_T hole) in VDCs
    • GEM checkout --   Nilanga Liyanage
      • First attempt at GEM commissioning
      • Identify Quartz detector shadows in GEM & VDC coordinates
  • A_T hole characterization -- 1 shift
    • Determine placement of A_T detectors (Priority activity) --   Bob Michaels, Dustin McNulty
      • Characterize acceptance on thin targets with A_T hole blocked & unblocked
      • Two or three accesses to block and unblock A_T hole
    • Parasitic GEM/Detector studies --   GEM & Detector teams
      • Accumulate statistics on detector pulse height
      • Learn to measure rates to 10% with GEMs
      • A_T hole alignment
      • Place A_T hole detector such that rate is ~ 100 times less than main detector (with thick target)
  • Water Cell & Optics -- 2 shifts
    • Absolute angle measurement (Priority activity) --   Nilanga et al
      • Sieve Slit runs
      • Angle calibration

    </UL>

    Lead Target Checkout (1-2 calendar days)

    • High Current Commissioning -- 1 shift
      • Production target checkout (Priority activity) --   Bob Michaels et al
        • 100 uA on thick Lead, monitor radiation levels, establish luminosity limits
      • Electronics commissioning --   KK, et al
        • Establish LUMI performance characteristics
        • Detailed measurements of various oversampling configurations
    • Parity Commissioning -- 1 shift
      • Parity Quality (Priority activity) --   Kent, et al
        • IA feedback, beam modulation ( low current modulation - dithering commissioning before CW )
        • Evaluate SAM regression performance
      • Beam monitor calibrations --  
        • Bulls-eye scan, fixed gain BPM calibration, BCM calibration
    • Q2 Measurement -- 1 shift
      • Establish Q2 measurement sequence (Priority activity) --   Dustin, Nilanga et al
        • Drift chamber rate measurement at a few nA
        • parasitic GEM commissioning
        • try to establish a rate in GEMs, especially in quartz shadow, at 10-100 nA
      • ARC energy measurement --  
    • High Luminosity Detector Commissioning -- 1 shift
      • Characterization of Integrating Detector response (Priority activity) --   KK, Dustin et al
        • Estimate detector rates & impact of A_T hole flux
        • Evaluate primary detector and LUMI noise peformance
        • Evaluate BPM performance; compare strip-line regression to cavity regression
        • Establish empirical figure of merit for A_T hole detector
      • Final parasitic GEM commissioning --   Nilanga et al
        • Compare predicted and measured integrating width prediction at moderate current on thick target

    Polarimetry Beam Checkout (1 shift)

    • Moller Beam Checkout -- 2 shifts
      • Moller magnet alignment (Priority activity) --   Moller team
        • Verify Moller magnet does not steer beam
      • Parasitic Compton Checkout --   Compton team
        • Feedback to MCC on beam quality
        • Simultaneous performance on Moller tune, compton background and sufficient raster

    Polarimetry Checkout (4-5 calendar days)

    • Compton Commissioning -- 8 shifts   Gaskell, et.al.
      • Beam Tune, Background reduction -- Bteam,
      • Compton Cavity Checkout --
      • Photon Detector Checkout -- CMU group
    • Moller Commissioning -- 8 shifts   Simona Malace, Don Jones, et.al.
      • Magnet Alignment -- 1 shift (swing)
      • Raster size and pulse-mode -- 1 shift (day)
      • Target commissioning - 3 shifts
      • Pulse-mode target commissioning - 2 shifts
      • DAQ checkout -- 1 shift

    Establishing Production (2-3 calendar days)

    • Production Checkout -- 2 shifts
      • Final detector alignment checks
      • Final LUMI/noise/helicity flip rate checks
      • Final beam modulation tweaks
      • Quick check for gross non-linearities
      • 4 hours longitudinal polarization production data
    • Transverse Polarization -- 4 shifts
      • Double-Wien Spin Manipulator Commissioning --   Joe Grames
      • Spin dance
      • 4 hours transverse vertical polarization production
      • 2 shifts transverse horizontal polarization production

    Total time: approx 15 days !   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.

    Important Activities after few days of production

    • Linearity Studies -- 1 shift   Kent Paschke
    • Background Studies -- 2 shifts
      • Scans of Septum Magnet and HRS Dipole
      • Thin Lead Target to check for inelastics at high-resolution
      • Thin C12 to measure diamond background
    • Possible scan of Q1 to optimize acceptance and verify that collimator defines acceptance.