[Ushiba, Lucia, Anamaria]

We started with a locked simple Michelson to work on ASC MICH loop. But we've been having trouble centering the ASC WFS QPDs. Last night's long lock puts the beam on the QPDs at P,Y (0.5, 0.5) for both QPD1 and QPD2 despite us centering them in bright sinple Michelson a few hours before. We decided then to move some output beam optic to bring the beam within PZT centering range, so we could make progress on the MICH loop. Then we had planned to go align the QPDs in situ, for full ifo positions.

However, when we moved SR2 and OMMT1 we saw the power on all four AS port PDs go up (2 ASC QPDs and 2 LSC PDs). This worried us for clipping the ifo output beam so we went to single bounce ITMX configuration and surveyed the SR2 and OMMT1 ranges. The attached two plots show the moves of SR2 and OMMT1 and their effect on the four PDs. There is a caveat that the ASC QPDs are almost off the photodiodes so sometimes when they drop, it's not a real loss of power at the AS port, which is why we trust LSC ones primarily (and they are DARM sensor).

The following table shows the increase in all PD power.

We also checked what the range is for these two actuators before we start clipping again:
SR2 P: 90->200
SR2 Y: 255->285
OMMT1 P: -500 -> -2000
OMMT1 Y: -700 -> 100

OMMT2 is not usable (no OSEM signals so probably no coil driver connection).

We calculated that with these moves, in order to properly center the ASC QPDs for full ifo we need to go (in beamsize units):
QPD1 P,Y: -1, 0.6
QPD2 P,Y: -1, +1
We will do this move tomorrow morning as well as check the whole AS table in case such a move made us close to the edge on some optic.

The DARM gain was reduced by a factor of 2.5 to relock FPMI. There may be some DARM improvement but it's too early to tell.