CREXAuxiliaryMeasurements

CREX Main << CREX Run Plan

WORK IN PROGRESS

1. Please don't worry if there is a needless test on here, or an important one missing, or bad prioritization.
2. Lets fix it

Optics and Q2

1. Energy Measurement (Doug) (non-invasive)
   • Priority High
   • look for 1e-3 accuracy. Non invasive.
2. Q2 measurement
   • Repeat of Q2 measurement, with improved pedestal noise control.
   • Detector counting mode.
   • S0 trigger
   • production raster and beam position
3. Optics Data
   • retake watercell,
   • retake optimization data
   • inelastic spectrum data

Backgrounds

1. Stubby Quartz / Blinded Quartz?
   • Longish access to setup and back out, but short data taking period (production conditions).
   • Replace detector quartz with superelastic stub or blinding cap (alternate US/DS and L/R)
   • Integrating measurement. Could normalize increased gain just by lowering beam current in production condition.
   • If surprising results found, continue test or plan second test
2. Rescattering measurement (~1 shift)
   • Detailed Rescattering Runplan
   • perhaps plan for late april?
   • repeat of previous measurements, but new optics and a crucial cross-check
   • Detune spectrometer up in momentum, to dump elastic peak into spectrometer wall.
   • Measure (integrating mode) signal in main detectors. Requires HV boot-strap to get higher gain (is 10x possible?)
   • should scale all spectrometer magnets.
   • At each dipole setting, also take data with nominal septum
   • Once the elastic peak is out of the focal plane, it should be possible turn on the S3 and S0 scintillator. This should be done when possible, and the T1/T2/T3 trigger rate recorded for each run.
3. Pole tip re-scattering
   • Requires investigation or planning - do we have an idea here?
   • Q2 or septum mis-tune, to increase interception on pole tip and improve poletip rescattering estimate
4. A_T detectors
   • Do we want to blind them again?

Detectors

1. Linearity Studies (PITA + current scans) (Caryn)
   • These are ongoing - should continue regularly. ~ 1 hour every 3 days.
2. Linearity LED tests
   • This will be studied off line

Other

1. Sign check
   • run Moller, Compton, and parity DAQ for quick PITA scan
   • Have we already done this? Parasitic with any PITA scan

Moller polarimetry

1. Repeat measurements
   • about ~30-60C. Goal: 1-1.5 shifts per measurement.
2. Q2 scan?
3. deadtime scan?
4. target position scan?

Compton polarimetry

1. No-target runs
2. Laser polarization optimization
3. Laser polarization flip
4. linearity studies