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User name vasulk
Entry time Mon Apr 29 11:40:27 EDT 2002
Entry number 301
keyword=Exodus NMR polarization in Transverse
This morning I conducted a NMR measurement for Exodus, which is in transverse pumping. So I needed to rotate the field to 0 degrees for the measurement. To extract the polarization, I needed to go back to the Temperature test conducted for Exodus at the beginning of March to find the calibration constant with the lasers off. Below is a summary of the temperatures and densities for that temperature test for the lasers off.
Laser state T_p T_t T_c n_t n_c constant (%/mv)
================================================
off 163.07 31.28 36.71 11.22 11.02 3.08
off 162.63 31.24 36.08 11.22 11.04 3.08
Analysis of the NMR signal gave a signal height of 11.38 mV, or 35.05% polarization. Note that the cell is not centered in the oven, which is why the polarization is lower than before (42.5% in long.).
legend for the table:
T_p: Average temperature from RTD 6 and 7
T_t: Temperature of target chamber from RTDs 1-5
T_c: Temperature of target chamber in pickup coils from RTDs 2-4
n_t: Density of target chamber
n_c: Density of target chamber in pickup coils
All temperatures are in degree C, and densities, in amagats