Temperature optimization

Goal

To optimize temperature for 3He polarization.

Previous study

summer 2010, using cell Boris, done by John Donaghy et al, note available in paper

current run plan

using cell Boris.

use three 30na coherent laser

holding field 25Gs, phi 180 (or 0? depend on polarization)

chose 8 pumping cell temp points from 180 to 250C

Then step by step, we do:

1. adjust ovan to desired temperature and wait for it to be stable, then turn on laser

(laser will heat up, find the ovan temperature relation with desired pumping cell temp)

2. measure NMR every 2 hours for 12 times (1 day), 3He should reach max pol now.

3. measure EPR once.

4. measure AFP loss. turn off laser, measure NMR every 2 minutes for 5 times.

5. measure depolarization. keep laser off, measure NMR every 1 hour for 10 times.

data

temperature: oven 220(?), pumping cell 217

1 round

1. NMR_He_20101205_171421, spin up 10x120m 
2. EPR_AFP_20101207_1533,  1 time measurement at max pol 
3. NMR_He_20101207_171051, spin down 5x2m 
4. NMR_He_20101207_171051, spin down 10x60m

2 round

1. NMR_Freq_He_20101212_160628, spin up 10x120m
2. EPR_AFP_20101214_1702,  1 time measurement at max pol 
3. NMR_He_20101214_171003, 1 time measurement at max pol 
4. NMR_He_20101214_171833, spin down 10x10m