sheila.dwyer@LIGO.ORG - posted 14:15, Thursday 11 September 2025 (86860)
IMC transmission degraded after power outage, and in 60W locks since the power outage
Compaing now to a time before the power outage, the ISS diffracted power is now the same (3.6%). The PMC transmission has dropped by 2%, and the PMC reflection has increased by 3.5%.
Looking at IMC refl, before the power outage when the IMC was locked with 2W input power.
| time | IMC refl | refl percent of before outage | MC2 trans | MC2 trans % of before outage |
| 9/10 8:12 UTC (before power outage, 2W IMC locked) | 0.74 | 317 | ||
| 9/11 00:22 UTC (IMC relocked at 2W after outage) | 1.15 | 155% | 312 | 98% |
| 9/11/1:50 UTC (after first 60 W and quick lockloss, IMC relocked at 2W) | 1.27 | 171% | 310 | 97% |
| 9/11 18:17 UTC (after overnight 60W lock)** had one IMC ASC loop off | 2.06 | 278% | 278 | 87% |
| 9/11 19:22 UTC (after all IMC ASC on) | 2.13 | 287% | 301 | 95% |
| 9/11 21:17 UTC (after sitting at 2W for 3 hours) | 2.03 | 274% | 303 | 95% |
The attached screenshot shows that the ISS second loop increased the IMC input power during the overnight 60W lock to keep the IMC circulating power constant.
Images attached to this report
