I took some data tonight for a quick look at what combinations of DC signals might be good to use for DARM, as an alternative to ALS before we're ready for RF.
I had the arms locked with ALS, PRMI with REFL33, and tried to move the CARM offset between plus and minus 1. The PRMI wasn't holding lock closer than about -0.3 or +0.6, so that is also a problem. Also, I realized just now that I have left the beam dumps in front of the transmission QPDs, so I had prevented any switching of the trans PD source. This means that all of my data for C1:LSC-TR[x,y]_OUT_DQ is taken with the Thorlabs PDs, which is fine, although they saturate around arm powers of 4 ever since my analog gain increase on the whitening board. Anyhow, the IFO didn't hold lock for much beyond then anyway, so I didn't miss out on much. I need to remember to remove the dumps though!!
Self: Good stuff should be between 12:50am - 1:09am. One set of data was ./getdata -s 1089445700 -d 30 -c C1:LSC-TRX_OUT_DQ C1:LSC-TRY_OUT_DQ C1:LSC-CARM_IN1_DQ C1:LSC-PRCL_IN1_DQ |