R. McCarthy, J. Kissel, L. Prokhorov

Richard has restored the functionality of the ETMX High Voltage ESD driver. In addition to simply turning on the high voltage, he had to disconnect and reconnect the temporary, Beckhoff binary input control cable for the "MSR" light to engage on the driver. Once the Beckhoff's binary control was restored, we were able to drive. 

After aligning the suspension, we briefly confirmed the functionality of the ETMX optical lever since it's health had not been check since being replaced (LHO aLOG 19290). We looked at an ambient pitch and yaw performance ASD (looked OK -- saw SUS resonances, no apparent combs, and a noise floor of sub- 1 [nrad/rtHz] above 1 [Hz]), and trending the SUM to check for glitches (I don't know what glitching does or doesn't look like, but over the past 6 hours the SUM time series does not at ALL look Gaussian). So still unclear whether the optical lever is perfect (i.e. still probably can't use it for damping), but should be good enough for now (i.e. measuring charge). 

Once the optical lever health was confirmed good enough, we drove a 4.7 [Hz] sine wave through each quadrant and confirmed, with a 5e4 [ct] amplitude, that ALL quadrants (even LL, which had previous been busted; LHO aLOG 19097, 19060). Looks like the replacement of the feedthrough (LHO aLOG 19221) was a success.

Nice work in-vac and CDS team!

Leo has begun to take charge measurements.