• Main INDEX
  • Monthly INDEX
  • PREV
  • NEXT
    Make New Entry, Make Followup Entry

    User name Yi Qiang

    Log entry time 10:18:07 on November 11, 2008

    Entry number 248118

    This entry is a followup to: 248113

    keyword=EPR Correction

    The correction is based on the Lock-in output. I found out (after I turned off the laser and oven :S ) that the lock-in output on the high frequency side has a -150 kHz off set which means there is also an offset in the frequency. And the slope we obtained from FM test is 1.028uV/kHz*10000mV/500uV = 20.6 mV/kHz, therefore the frequency offset is -150/20.6 = -7.28 kHz.

    The frequency difference in the EPR test is 47.73 corresponding to 38.7% polarization. After taking this offset into account, the real frequency difference is 47.73+7.28 = 55.01 and the polarization is 44.6%. So the calibration constant is also corrected from 1.258 to 1.45 %/mV. The registry has been updated with the corrected value.

    A copy of this log entry has been emailed to: jpchen@jlab.org, chiran@jlab.org, jinhuang@jlab.org, yqiang@jlab.org