sheila.dwyer@LIGO.ORG - posted 21:14, Thursday 25 May 2017 (36439)
symptons that alignment references are not good
Jeff K, Sheila
Here are some symptoms we have that our initial alignment is not giving an alignment that is good enough to get through the CARM offset reduction.
1) REFL power drops too early in the acquisition sequence, because the recycling gain is low and the CARM offset is smaller than it normally would be.
| Guardian state |
LSC-TR_X/Y_NORM_OUT (arm power normalized to single arm lock) |
REFL power/ REFL unlocked (good enough alignment) | Refl power when alignment was too bad to lock |
| CARM on TR | 1 | 100% | 100% |
| CARM 15PM | 200 | 82% | 74% |
| CARM 10 PM | 450 | 60% | 40% |
| 850 | NA | 23% |
2) AS port camera looks bad just before DHARD WFS come on (you can see misalingment modes, Jeff got a picture to attach)
3) When we switch the AS36 Matrix while offloading the DRMI ASC, the sideband build ups get better.
We are making progress, update coming later.
Images attached to this report
