Nic, Jenne, Evan

In spite of the bad POPAIR situation, we were able to get DRMI to lock by increasing the whitening gain of POP18 (from 12 dB to 45 dB), and by lowering the trigger thresholds for MICH by a factor of 10, and SRCL by a factor of 5.

After DRMI locked, we were able to optimize the buildups of POP18 and AS90, mostly by moving PR3 positive in pitch, and then compensating by moving PR2 negative in yaw. In this way we increased the buildup of POP18 by a factor of 45. (We then undid the extra analog whitening gain.) So this seems to support the idea that our issues are caused (at least partially) by misalignment of the power recycling cavity.

We went onto the table and again tried to resteer onto POPAIR_B, but we got only 10 % more power on the PD. POP18 is now at about 6 ct (normalized), whereas we expect about 300 ct for DRMI without arms. So there is still a missing factor of 50 somewhere.

We measured the OLTFs of PRCL, MICH, and SRCL, and they seem fine. So the DRMI LSC seems healthy as far as we can tell; there's just some problem with the POP path.