J. Kissel

Here's your weekly broken record. Time to change the ETMX and ETMY bias sign!

Several quadrants of the H1SUSETMX and H1SUSETMY's TST L3 ESD systems show an effective bias voltage of around 40 [V], which is roughly 10% of the request / applied bias voltage of 430 [V]. This means the actuation strength is 10% different from its value in late June when we had last herded the effective bias voltage to 0 [V] and we'd hoped to begin the campaign of regular bias flipping (see LHO aLOG 27890). 

We're still waiting for a robust enough interferometer / acquisition sequence to declare we're happy (and probably also for me to be in the control room for a non-Tuesday late night when we're ever happy) to flip the bias sign and debug why we had troubles with ALS DIFF and switching to ETMY (see LHO aLOGs 28362 and 28152).