Stefan, Craig, Peter
We applied DC Bias to the ESD of both ITMs, ranging from positive to negative full scale (+437 V to -437 V). Looks like there might be a very small increase in low frequency DARM noise for +437 V bias on ITMY (see attached plot), but for all other applied biases there was not even such a hint of a noise increase.
This morning we also re-tested the effect of ETMY ESD bias. No effect visible in DARM in changing bias from 0 V, to +400 V, to -400 V.