gabriele.vajente@LIGO.ORG - posted 14:47, Thursday 13 October 2016 - last comment - 16:48, Thursday 13 October 2016(30508)
Alignment vs jitter noise
In brief, no success. In details, here are some alignment tweaks trief over the last couple of days:
- moving SRM in pitch reduces the jitter peaks at 200-400 Hz, at the price of worse sideband powers
- moving IMC DOF_1_P (offset of +400) reduces a lot the peaks, but a the price of decreasing the IMC transmission. SRM had to be moved to keep reasonable sideband buildup
- moivng MICH both in pitch and yaw had not clear effect
- going to the best CSOFT offsets that Jenne found helps a bit.
The decrease of range in the last lock was due to a misalignment of the SRM.
Can we roughly quantify this in m/rtHz/rad?
Moving SRM by ~20 urad reduces the noise by a factor ~2
A bit more like a factor 3 of noise reduction when moving IMC_DOF_1_P with an offset of 400, don't know the calibration