User name Yi Qiang
Log entry time 20:51:27 on October 25, 2008
Entry number 244663
keyword=Some hints on current polarizationBy comparing the pickup single from target chamber to water NMR results, our current polarization is only about 3%. http://spin.jlab.org/GenericLog/NMRField_25-10_16-39-23.html We checked the polarization of the two Q-wave plates by rotating one by 90 degrees, and observed very quick depolarization, therefore the Q-wave plates are supposed to be good. Another possible is the BB magnetic field, previous field was set up assuming BB field on which will bring about 2.5 degrees tilting of the holding field and this will have quite large screw effect on the optical pumping. The problem was corrected and now we are doing another NMR spin up test.
A copy of this log entry has been emailed to: jpchen@jlab.org, chiran@jlab.org, zhangyi@jlab,org, jinhuang@jlab.org, zhangyi@jlab.org, yqiang@jlab.org
Target chamber NMR signal
