Now that ETMX is back to vacuum, I measured a trend of the effective test mass charge voltage over 3.5 hours. The sensor was the oplev, since there is no cavity. I was told by Jeff K, who was told by Richard (or was it Kyle?) that the ion pump is valved out. The pressure was about 1.5e-6 torr, pumping with the turbo for about 2 days since the last vent.
The first pdf shows the charge seen the pitch and yaw oplev signals from excitation in each ESD quadrant. The second pdf shows the deviation from the average of each quadrant - oplev siignal pair, e.g. pitch from UL exc, etc. The largest deviation is -12 V. Most of the data is within +-10 V.
The charge measuring script is
/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/Scripts/ESD_UL_LL_UR_LR_charge_07-H1.py
The charge analysis script is
/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/Scripts/ESD_UL_LL_UR_LR_analysis07_H1.m
The charge trend script is
/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/Scripts/Long_Trend_H1.m
Yes, the ION pump is valved out. You can see on the EX Vacuum MEDM screen that IP12 is registering 4 decades better pressure than PT510. Therefore it is isolated from the BSC volume.
https://lhocds.ligo-wa.caltech.edu/screens/png/H0VE_EX-current.png