Jeff Kissel, Kiwamu Izumi, Jenne Driggers, TJ Shaffer
The two 6+ earthquakes in Alaska along with the front end restarts did a number on us, but Jeff K and Kiwamu worked hard and we are now back to Observing at 68Mpc.
I arrived on shift with initial alignment just finishing up. We could not go past LOCKING_ARMS_GREEN without damping the severely rung up bounce modes, so we spent some time damping those and trying to get them below the noise. After we were able to move on from there, we got DRMI after a handful of tries. We stopped at RF_DARM to damp the bounce modes further, and then check on the OM alignment at ANALOG_CARM. We then had to engage the SOFT loops slowly, per Jenne's suggestion. At this point we could see that the roll modes were also very rung up, and knowing this, still proceeded to lose lock at ROLL_MODE_DAMPING. Doh.
So I ran through the whole thing again, and this time I damped the roll modes by hand. The rest of locking was smooth sailing.
Now I can finally eat.
Had to accept a bunch of SDF diffs.
SEI - Hepi had some Tramps and setpoint diffs, and the ISIs had some filter differences.
SUS - A few differences with setpoints
ASC - IMC PZT offset diffs
Actually the earthquakes were in BC, Canada - that country that borders the US to the north ( or east of Alaska).
The SDF diffs on HAMs 2 and 3 are because these chambers (for reasons we don't understand) can't have their guardians change gains on the GS13s. On these chambers it works just fine to use the SDF system to revert the GS13 gains, if you do them all at once. This used to also be able to be set from the Commands screen on the chamber overview, but the script that does the switching was written in PERL (sensor_hilo in userapps/isi/common/scripts), so now it doesn't on our new Debian workstations. There is currently no easy way to reset the gains for these chambers.