Difference between revisions of "Pol He3 Target Meeting November 23, 2020"

Revision as of 15:59, 23 November 2020

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

Melanie

Almost completed d2n calibration cross-check
When the info becomes available, be sure to update results with the final AFP loss for each cell/configuration, and proper PC and TC temperature values derived from the temperature tests
- Junhao and Mingyu should make and update an appropriate database for this
Identify and separate "problematic" EPR measurements to discuss as a group, and to investigate the suspected issue (like obtaining necessary EPICs values for field instability, for example)

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

Bill

Presented Field Mapping measurements done in September 2020
- 11 and 14 degree settings weren’t done with everything on; only the 18 degree measurement was done with all the coils on, so is the only setting that can be compared to Murchhana's compass measurement
- general trends are the same everywhere between both measurements
- transverse and longitudinal orientations were equal to or less than 0.5 degree off from values found from the compass measurement
- the takeaway is that we can trust the compass measurement results within 0.5 degrees; ideally would want to be within 0.1 degree confidence level

@@ Line 1: / Line 1: @@
 <b> Members present: Jian-ping, Arun, Bill, Murchhana, Mingyu, Melanie, Junhao, and Dave </b>
+Melanie
+*Almost completed d2n calibration cross-check
+*When the info becomes available, be sure to update results with the final AFP loss for each cell/configuration, and proper PC and TC temperature values derived from the temperature tests
+**Junhao and Mingyu should make and update an appropriate database for this
+*Identify and separate "problematic" EPR measurements to discuss as a group, and to investigate the suspected issue (like obtaining necessary EPICs values for field instability, for example)
 Junhao
@@ Line 14: / Line 20: @@
 ***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
+Bill
+*Presented Field Mapping measurements done in September 2020
+**11 and 14 degree settings weren’t done with everything on; only the 18 degree measurement was done with all the coils on, so is the only setting that can be compared to Murchhana's compass measurement
+**general trends are the same everywhere between both measurements
+**transverse and longitudinal orientations were equal to or less than 0.5 degree off from values found from the compass measurement
+**the takeaway is that we can trust the compass measurement results within 0.5 degrees; ideally would want to be within 0.1 degree confidence level