RunPlan

PREX Run Plan for   Commissioning   and   Auxiliary Measurements

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

See also the Daily Run Plan and Earlier Daily Run Plan

The experiment is approved for 30 PAC days; there are 2 weeks of "commissioning" listed, and then an additional 61 days for production.

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; see the HOWTO webpage for shift worker instructions for the 2010 run.

Spillover from Beam Restore

• Basic Beam Setup -- 1 shift   Jay Benesch, Bteam
  
• Source and Parity Quality Beam -- essentially done   Kent Paschke, Mark Dalton, Rupesh Silwal
  

Low Current Checkout with Water Cell (2-3 calendar days)

• Septum checkout (Sieve IN) -- 1 shift
  • Septum Commissioning (Priority activity) --   Bob Michaels, John LeRose
    • Verify septum does not steer beam
    • Thin target, first VDC data at 1-2 uA
  • Low-current cavities --   Bob Michaels
    • Check hardware at 1-2 uA
  • Target alignment check --   Bob Michaels
    • Check spot on BeO viewer
    • Put in Ta or ultra-thin C12 target
    • Scan few mm up-down, left-right, verify from rates we're not hitting a frame.
  • VDC Checkout --   Dustin McNulty, Alexandre Camsonne, Bob Michaels
    • Look for sieve holes; first check on optics
  • Quartz detectors checkout --   Dustin McNulty, Piotr Decowski, Jon Wexler
    • Calibrate detector x-y movers in VDC coordinates
  • GEM checkout --   Ole Hansen, Alexandre Camsonne, Nilanga Liyanage
    • First look at noise, pulse-heights, tracks
• Spectrometer checkout (Sieve OUT) -- 1 shift
  • Low-current cavities (Priority activity) --   John Musson, Zafar Ahmed
    • Need before subsequent program, especially Optics and Q²
  • VDC Checkout --   Dustin McNulty, Alexandre Camsonne, Bob Michaels
    • First spectra on specific thin targets
    • Learn to measure rates to 10% and study rate dependence effects
  • Quartz detectors checkout --   Dustin McNulty, Piotr Decowski, Jon Wexler
    • 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 --   Ole Hansen, Alexandre Camsonne, 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

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, Luis, Paul et al
    • Establish LUMI performance characteristics
    • Detailed measurements of various oversampling configurations
• Parity Commissioning -- 1 shift
  • Parity Quality (Priority activity) --   Kent, Rupesh, Luis, Dustin et al
    • IA feedback, beam modulation ( low current modulation - dithering commissioning before CW )
    • Evaluate LUMI regression performance
  • Beam monitor calibrations --   Diancheng Wang, Xiaoyan Deng
    • 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 --   Arun Saha
• High Luminosity Detector Commissioning -- 1 shift
  • Characterization of Integrating Detector response (Priority activity) --   KK, Jon, 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 --   Ole, 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
  • Access to remove water cell --  Dave Meekins
    • begin cold target operation

Polarimetry Checkout (4-5 calendar days)

• Compton Commissioning -- 8 shifts   Sirish Nanda, et.al.
  • Beam Tune, Background reduction -- Bteam, Alexandre Camsonne
  • Compton Cavity Checkout -- Sirish et.al.
  • Photon Detector Checkout -- CMU group
  • Electron Detector Checkout -- Alexandre Camsonne
• Moller Commissioning -- 8 shifts   Sasha Glamazdin, 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   Rupesh Silwal, Kent Paschke, Luis Mercado
• 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.