[Gabriele, Rana, Jenne, Jamie, Lisa, Zach]
We tweaked some things after dinner, and our locks got longer (~10sec) and more frequent!
What happened / notes:
* Increased analog gain from 15dB to 27dB for REFL55 I&Q.
* No analog whitening during lock acquisition. (Need trigger + wait so whitening comes on after ~1sec...but this is not our limitation right now).
* Limit MICH and PRCL control to 5000, so that we don't kick optics too much, which makes them take too long to settle.
* ITMX and ITMY Vio2 filters turned off (PRM still has it on) in the SUS-optic_LSC module.
* MICH and PRCL DoFs triggering on POP22I, with levels 200 & 50. FMs 4&5 always on.
* MICH and PRCL FM2 triggering on POP22I with levels 400 & 50.
* MICH gain = -0.200
* PRCL gain = +0.150
* MICH and PRCL normalization using POP22I, with matrix values 0.00160 . This value is ~1/600, where 600 was the peak value of POP22I_ERR.
* REFL 55 phase set back to -15, to minimize PRCL signal in I phase.
* Checked signs for ITMX and ITMY in output matrix for MICH. Lock MICH using only ITMX or ITMY, find sign to hold on the dark fringe for each. +1 for ITMY, -1 for ITMX was correct.
* Tweaked up the oplev servos. See separate elog 8362. May need more tweaking, such as increasing the UGF, engaging 1Hz resonant gain.
* May need better coil actuator balancing on suspensions at 1Hz.
* Found a weird thing in DTT, which went away after closing and reopening, when looking at time series. Sometimes we would see a square wave-like jump in the signals, all signals at the same time, with a frequency of 16.6Hz. This was not present in other data retreival programs, like Jamie's getdata python script.
* We are not sure right now why we are falling out of lock. We need to investigate more signals, to try to figure out what our current problem is.
* Reduced the amount of misalignment with the "misalign" script, to reduce hysteresis.
To Do / ideas:
* Calibrate oplev signals - see if one optic is moving more than others.
* Calibrate ERR and CTRL - look at CTRL in meters, see if cavities are moving around like crazy.
* Calibrate POP22 using something like an AM laser modulation trick into units of PRCL SB gain. Compare with expectation - are we locked optimally, or do we have more power that we can be getting out?
* Try feeding back PRCL CTRL to MC2, to make the laser to follow the power recycling cavity, in hopes of reducing angular motion. Rana tried this quickly with a 1 in the output matrix, but this kicked the MC out of lock - need to try smaller values.
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