cheryl.vorvick@LIGO.ORG - posted 20:13, Thursday 31 January 2013 - last comment - 09:28, Friday 01 February 2013(5344)
IMC power budget completed tonight:
- Giacomo, Cheryl
Alignment of the IMC, and IM3 and IM4, increased IFO REFL from 106mW earlier this week to 147mW today, giving 90% power coupled into the IMC. In our first measurement, the IMC alignment had drifted away from optimum, and the the IFO REFL beam was clipped on the baffle in front of IM4.
Power budget:
| Location | Power (mW) | Time | |||
| PSL before | 210 | alog #5100, 14 January 2013 | |||
| PSL | 178.3 | 1043721378 | 84.90% | of the PSL "before" | |
| IMC Refl Unlocked | 178 | 1043720171 | 99.83% | of the PSL beam | |
| IMC Refl Unlocked PosB | 2.11 | 1043719839 | 1.19% | of the REFL beam | |
| IMC Refl Locked (estimated) | 15.18 | 8.53% | of the unlocked beam | ||
| IMC Refl Locked PosB | 0.18 | 1043719643 | 8.53% | of the unlocked beam | |
| IM1 Trans | 0.072 | 1043719495 | |||
| IM4 Trans FWD | 0.0216 | 1043718853 | |||
| IM4 Trans BWD | 0.33 | 1043718853 | |||
| Park | 147 | 1043717883 | 90.29% | of the power coupled in the IMC |
Comments related to this report
I should add that before this power budget was made I aligned the IMC and got IMC REFL down to 48 " counts"', and after the IMC broke lock and relocked IMC REFL was at 34 "counts"', which is a big improvement from our previous low of 50 "counts". To get this low IMC REFL I was down to aligning MC1, MC2, and MC3 at the level of +/-1 on the offsets that control the pitch and yaw of the mirrors, which means the alignment is close to optimum by human servo. The IMC stayed locked overnight, and temperature oscillations drove IMC REFL up and down, and throughout the night the low returned to 34 counts.