After discussing with Jenne this morning, I have flipped the sign of the ETMX ESD lock bias voltage from -450V to +410V to reduce the charge build up in the optic. I will keep this settings for a week or two and measure the charge on the optic. If the charge gets reduced, then will continue with this until we are ready for locking the IFO - will revert the settings to nominal values at that point. Attached below is a trend of the lock bias offset and ESDAMON_DC_OUT, which shows the changes I have made today.
I have made some adjustments to the L3 HV mon for ETMX after having some email discussions with Jenne. The latest settings is opposite sign and value (of high voltage) of what we have during Observing run (and not Down state - which is what I did earlier).
The first screenshot I have attached below shows the sign and value (positive 123V), when we were at Observing.
The second screenshot shows latest settings, i.e. negative 123V 450V (full negative). I will revert this once we go back to locking the IFO.
