Make New Entry, Make Followup Entry
User name Chiranjib
Log entry time 15:03:31 on November 15, 2008
Entry number 249006
Followups:
keyword=EPR Calibration/ SPIN UP for TRANSVERSE + / POLARIZATION etc.I did an EPR calibration after the spin up is done for 230C with
Transverse pumping. The plots are attached. The polarization at this hour
is 65.5% and the calibration constant is 1.49501.
Actually I destroyed the polarization to some extent while making EPR
AFP work. With the current lock in sensitivity of 1mV and FM deviation
100Khz/V, it seems its really hard to lock the signal at all. May be its
because the polarization is too high. Note that the PI Gain is 0.13
(absolute) at that point and the RF amp was -7dBm.
Then I increased the lock in sensitivity to 2mV and it still did not
work. And then I decreased the RF amp to -10dBm and increased the FM
deviation to 120 KHz/V. It worked fine after that.
On the other hand , a spin up plot for the transverse + shows 4.44
hours of spin up time .
The max NMR expected is ~47.75mV.
So *naively* speaking our maximum polarization could be
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* 71.4% *
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A copy of this log entry has been emailed to: jpchen,yqiang
EPR FM sweep
EPR AFP sweep
POLARIZATION / Calibration constant
SPIN UP @230C / TRANSVERSE +/75 W
