after about 2 hours of trying to damp mode 3 with the filters that H1 has been using, with little to no effect, I talked to Jeff about changing the filters, since mode3 damping had always been mariginal.
Changes to IX mode3:
- removed 1.5KHz filtering that was from some previous attempt to damp at the frequency
- moved the filter I made, title n504.719, to FM2, next to the filter we're currently using, FM1
- moved +/-60deg filters to FM8 and FM9, and adjusted their gain to restore gain = 1 (was found at 1.5)
- created +/-30deg, in FM6 and FM7
- moved the 100db gain to FM10
- saved and loaded
- Jeff made changes to the filtering phase and gain, over the span of about an hour
- the mode peak in darm was reduced, eventually all the way to background
- filter bank gain is now -40
- I've updated lscparams to reflect these changes, and they were successfully loaded by guardian before reaching NLN
Attachment 1: IX mode3 from abandoning the old filters to damping at relocking H1
- the first vertical marker shows the end of trying with the old filters to the left, and the new filters working on the right
- mode3 used to have +60deg, and now runs with -60deg
- the second vertical marker shows H1 relocking with the new filters/gain, and successfully damping
Changes to IX mode2:
- updated gains in +/-60deg and +/-30deg, renormalized to a gain of 1
- saved and loaded
- mode2 is running with the same gain as before, -25, though higher gains were used to damp after the ring up
Attachment 2: IX mode 2 from unsuccessful redamping to (mostly) successful damping at relock
- IX mode 2 damping is not reducing the peak to background, but is keeping it from ringing up (needs more work)
Other modes, other optics, damped by Jim:
- EY modes 1 and 6
- IY mode 15
- all were rung up to greater than 5 on the RMS
- all successfully damped at relocking H1
Attachment 3: IY mode 15
Attachment 4: IY modes 1 and 6
- Jeff, Cheryl, Jim