DVCS November 1st meeting

Remaining issues / Progress

• Moller no sign flip with half wave plate
  • Moller sign did not change with half wave plate on one measurement, might be IOC / hardware issue. We will try to check the Compton asymmetry with half wave plate
  • ad-hoc test would be to check all the DAQ (HRS/Moller/Compton) with large asymmetry charge and do half wave plate change - Or we will do this test later with half wave plate change just to check the signs for the different DAQ
• Optimization of Wien angle during QWeak down ?
• Trigger efficiency
  • Gas Cerenkov efficiency - 3 % inefficency - Accuracy of measurement
  • S2m efficiency - Some paddles were less efficient - Shift of one S2m paddle ( pedestal update )
  • Analysis of single arm data
• Normalization/deadtime
  • logic module output
  • logic module bit patterm
  • scalers
  • bit pattern TDC working
  • Random trigger understood  ?
• Helicity
  • Ring buffer errors - recoverable ?
• DAQ
  • Buffering seems to work - Sync ADC deployed - Would like access to add the VME ADC front end busy, need ECL cable, NIM fan. Crate synchronzation seems ok so far.
  • additionnal sync signal in ARS
  • ARS spares
  • Pedestal noise issues seems by Ben - Is it in the data ?
  • Full setup in DAQ room
  • Calibration of trigger module failed , reason still unclear - Missing Mezannine board
  • Add multiple triggers ?
• Run list
  • How much data was taken ? Data quality
• Low current vs high current
• Calorimeter
  • calibration : pi0 ( Eric out of town )
  • radiation damage
• BCM calibration

Proposed plan

• continue Kin3 4 pass until VME320 work
• switch to Kin 2 low to test VME320 with H and D, low current, high current, buffered and unbuffered ( might be ready tomorrow or Wednesday )
• Trigger ( still not clear how long it will take, Ben will start looking at the code maybe tomorrow , rough estimate one week)
• in parallel full setup in DAQ room for logic module check.
• single arm data with trigger readout to check trigger efficiency
• try coincidence ( middle of Kin2 H or D )
• pass change ( 3 pass or 5 pass ? )
  • complete Kin I low and optics data
• Go to 5 back to 5 pass ?