Pol He3 Target Meeting November 23, 2020

Members present: Jian-ping, Arun, Bill, Murchhana, Mingyu, Melanie, Junhao, and Dave

Junhao

• Working on deriving the target polarization per run. Need the following quantities:
  • NMR amplitude of last NMR measurement before the run
  • EPR correction based on the current field direction and magnets condition
  • Convection correction: target chamber polarization correction based on equilibrium condition
  • AFP loss on target chamber
  • pNMR loss on target chamber
  • polarization-evolution-based correction:
    • time: spin up time constant and observed polarization deterioration
    • charge: accumulated charge on target since the last NMR measurement
    • beam current
    • special conditions: laser status, QWP status, etc
• AFP loss study done on longitudinal configuration with 6V convection heater; to get the true AFP loss, we need to also correct for the convection itself