I haven't had time to post this because of the wind fence work, but I haven't been able to finish the commissioning of the HAM1 ISI because of a 70-ish hz feature in mostly the X and RZ plants. I didn't see or appreciate how large this 70hz feature was in my close out measurements before doors went on, and it's making the loop design very difficult. I was trying to notch the loops to make the ISI work, but 70hz is very close to the nominal 30hz loop ugf. The X,Y,RZ and Z loops are marginally stable right now, and the 70hz feature gets injected into the IMC when ALS is locked. I think that I can get the loops working, but probably with less gain than we would otherwise get.
Attached PDFs are the loops currently installed, the ISI is set to not use the RX and RY loops, but the X loop is probably ringing at 70hz when the ISI is isolated. We are currently running with just the damping loops though.
I was able to get the ISI running yesterday, by adding notches to the loops at ~72hz, reducing the boost gain and reducing the ugf of the loops to generally around 22-25hz. The ISI was running most of yesterday and through the night, until I shut it off for the HAM1 vent this morning. Attached are the loop design plots for the loops that are running now.