Sheila, Camilla, Elenna, TJ
- Picking up where we left off in 84554, we started by checking our alignment:
- ran TMS + ITM baffle PD scripts
- both ETMs were off in yaw, adjusted, locked green and ran ETM + TMS green WFS. ALS-C_TRX is at 1.2, TRY is at 1
- Camilla realigned IMs, to where they were according to top mass osems at our last DRMI lock before the vent. She adjusted IM3 to bring the position on IM4 trans QPD back to where it was at that time, and we had flashes of 0.6 in the LSC_TR_X channel (normal value is 1, this should be good enough to lock).
- Pop45 has no error signal. Turned on sidebands (!), reset POP 45 dark offsets, which are hardcoded in ALIGN_IFO for this state, adjusted POP45 demod phase by 90 degrees, realized this was the wrong sign and finally adjusted it to -78 degrees which is accepted in SDF, then xarm locked.
- TJ and I went to the table in the meantime, and aligned the PSL beam through the ALS SHG. TJ aligned the COMM beatnote easily, +3dBm, took a break for a big EQ.
- The SHG green power monitor PD doesn't seem to be working, we tried to follow the cable but got confused, the digital channel doesn't respond to room lights or phone.
- Locked PRX, Elenna aligned PRM by hand, Sheila and TJ realinged REFL air path (for the first time).
- After lunch we aligned DIFF beatnote getting to -11dBm, easiest to start by co-aligning the ghost beams off the PD. Camilla found this new technique for this normally difficult alignment that seems much easier than our usual approarch.
- The POP and RELF air beams were only ~1.5" or so apart on the top periscope mirrors. We are unsure why this changed and checked the alignments from when they were we aligned to the top periscope mirrors 84344.
- Camilla and I couldn't bring the mirrors close enough to have one mirror on each beam so we moved the periscope ~1" in +X and 1" in -Y to ge them both on the +X top periscope mirror. They are on their separate lower periscope mirrors.
- We aligned the REFL path and checked all stray beams were dumped
- We aligned the POP path onto, the beam was hard to see but we got some signal on POP A, we expect enough to lock with, we can optimize alignment later.