Hall C has decided against doing a Moller.
In anticipation of the Moller run, earlier today, after setting the Wien and optimizing the Injector for two beam operation (for Halls B and C), Yan re-optimized the Injector to support three beam operations, adding beam from A laser to serve as a shadow beam during the measurement. The three beam set up is less optimal for high current running for Halls B and C, so we have reloaded the optimized two beam operations settings.
Fig. 1 40 uA CW beam from C laser to ILD
Fig. 2 100 nA CW beam from B laser to FC2
Looking at the first production beam currents in parity runs 13732-13733 (15:50-17:50), the Hall C charge asymmetry was leveling off at about -2500 ppm.
At 18:13, after about 23 minutes of run 13734, I changed the Hall C IA setting from 61000 to 48150, which ought to bring the asymmetry close to zero. Unfortunately, this change was just after the beam stopped to reconfigure the machine for high current beam without witness beam (https://logbooks.jlab.org/entry/4230310) so we can't check the new asymmetry yet.