Ryan S, Sheila, Camilla
NLG looks good, green and IR flashes a factor of 3 below O4 levels. Can improve Green flashes only by ZM2 PSAMS.
Increased Seed power from 0.3mW to 75mW (as used in vent). With sliders (FC1, ZM1-6) in settings they were we had 0.4mW on SQZT7 IR PD, when I moved sliders back to as during the vent attached, this increased to 1mW as expected how we left sliders at end of the vent.
Adjusted sqzparams.py opo_grTrans_setpoint_uW to 10.5 as this is typical value with no ISS, then checked NLG 76542. Still OPO ISS would not work. We expect it's as AOM alignment needs work.
| Time | OPO Setpoint | Amplified Max | Amplified Min | UnAmp | Dark | NLG |
| O4 87385 | 80 | 0.0134871 | 0.00017537 | 0.0005911 | -2.57e-5 | 21.9 |
| Now | 10.5* | 0.0044498 | 0.0002008 | 0.0001683 | -2.18e-5 | 23.4 |
*OPO Trans power is lower than O4 as is this is just leakage from OPO mirrors which now have different transmitted powers as the OPO has been swapped.
Adjusted wave-plates in Green pump path to minimize rejected power.
Looking at FC
Ryan touched up FC1 and FC2 alignment, we were only getting green flashes on H1:SQZ-FC_TRANS_C_LF_OUT_DQ of 6 and IR flashes on H1:SQZ-FC_TRANS_D_LF_OUT_DQ around 0.04. We then did a walk of ZM2 PSAMS and ZM2 Pitch, with touch ups of FC1 and FC2 and ZM2 yaw. Once we got gren flashes >12 we were able to stay in SQZ_FC at GR_SUS_LOCKING. We started at ZM2 PSAMS strain gauge 6.55V and sliders as in vent (attached). We got to ZM2 PSAMS at 8.3V with sliders and scopes as attached, this gave us green flashes of 30 and IR flashes of 0.2, plot. In O4 we had green flashes ~60 and IR flashes ~0.7, plot. We are still a factor of 2 or 3 below O4 with what we expect is an incorrect ZM2 PSAMS setting.
We do not think that the ZM2 strain gauge should be different as no offloading was done to ZM2. When we put ZM2 back to nominal 6.55V and touch up alignment attached, our max FC green flashes were 20, IR flashes 0.2. But at this location the IR light on SQZT7 is decreased, plot comparing best green flashes to original vent sliders. We later with these vent sliders + FC2 changes got IR flashes to 0.4, but the IR camera showed not a real beam, just a stripe fo light as we saw in February (maybe the beam is at the edge of the FC2 coating).
