Writing this alog on behalf of most of the control room...

After we redid the input matrix for CHARD and INP1 10W, we checked the PRC2 and INP1 bandwidth. We were also concerned about the overall gain of CHARD P and Y since they seemed to be way too low

• We stepped the offset of INP1 pitch and yaw as a rough bandwith measurement. We found that INP1 yaw gain to be too high by a factor of 10, and the INP1 P gain to be just fine.
• we ran OLGs of PRC2 pitch and yaw, and found the gain to be about a factor of 3 too high for both, which may have been responsible for some 0.8 Hz buzzing we saw in the ASC signals whenever we tried to raise the CHARD gains
• After this, we were able to raise the CHARD P gain to achieve a UGF around 3 Hz, as desired.
• We were still unable to raise the CHARD Y gain to a reasonable value without ringups
  • it seemed anywhere between 20 and 40 dB too low, but it was hard to tell from the measurements.

We decided to power up anyway, and saw that the pitch ADS was able to run fine, now that the CHARD pitch gain was nominal. However, yaw ADS still had problems during move spots.

• We stepped up power from 10 W by hand, and then ran through the power 25W state by hand (which also changes loop gains, engages soft yaw, etc).
• Then we ran move spots successfully- towards the end of the state is where we had to drop the yaw ADS gains due to an instability.

Everything looked good, so I took us up in power from 25W to 60W, stopping frequently to check for instabilities. We made it, but again the ADS was unstable, so Georgia used the Camera servo guardian to move off the ADS to camera servos, and everything was fine.

I stepped through lownoise ASC by hand, skipping the lownoise steps of CHARD P and Y since those gains were not nominal.

• Then, I rescaled the overall lownoise gain of CHARD P and engaged its lownoise filters, no problem.
• I measured the CHARD Y OLG and found the gain  still very low. But this time I could step it up from 3 to 300 as needed and the higher gain made the buildups look a little better.
• Since the gain was back to nominal, I scaled to the lownoise gain and engaged the lownoise filters.
• The gain scaling is saved in the guardian.

Lots of the of the usual wobbly stuff in the ASC and buildups at high power, but the overall alignment and control looks good: PRG is still around 50 at full power.

We then ran through lownoise coil drivers and the ETMX ESD transition. We had one guardian error at the end of TRANSITION FROM ETMX due to divide by zero error since the convergence checker looks for something that is like [ADS error signal / ADS CLKGAIN] and the ADS CLKGAINs were zero. Georgia and I fooled the guardian by setting the CLKGAINs to 1 momentarily, and then undoing them once the state completed.

We ran all the way through LOWNOISE LENGTH CONTROL, although the LSC feedforward is no longer well-tuned, so I turned it off momentarily so we could check OLGs.

The LSC feedforward is currently so bad that we should go from-scratch when we retune it instead of the iterative method.

We had a fast unknown lockloss while sitting in this state- no one was doing anything and we don't see an obvious cause.

We think we have properly SDFed and guardianized all changes from today.

My only worry: we were not able to raise the CHARD Y gain until we reached maximum power, but obviously we are having ADS stability issues since this gain is too low. Currently I have set the guardian to have what I think is the "correct" CHARD Y gain (300 once all loops are closed), but if it's too high, drop it back to 3.

Recommended to do list:

• check PRCL OLG
• Check PRCL/SRCL/MICH sensing at high power
• consider turning off some LSC notches, many seem unnecessary
• Run MICH/SRCL (PRCL?) LSC feedforward measurements, tune, etc
• determine if we want to run camera servos sooner during power up/locking process
• Check SRCL offset