Stefan, Matt, Evan
This afternoon and this evening we made some more attempts at locking DRMI3f+arms, with the goal of implementing a handoff from ALS to sqrt(TRX+TRY).
Below are some issues that we’ve noticed.
ALS:
DRMI:
ISC_DRMI
guardian seems to get stuck on the OFFLOAD_DRMI
state. It engages the M2 locking filters in PRM and SRM, but then does not move on. For the time being I’ve short-circuited the run
portion of the state so that it directly returns DRMI_1F_OFFLOADED
.ISC_DRMI
guardian.Alignment:
Other:
Good UTC time for DRMI3f+arms starts 2014-11-22 06:48:00
I think Evan means "2014-11-23 06:48:00". About the L2P on ETMX L1, it is not just the transient that appears to be problematic. This is a quick look at the first hour of data. ETMX gets badly misaligned once corrections are sent to L1: the green power decreases down to half its maximum level (first plot). The second plot shows corrections sent to L1, while the third plot shows the induced pitch misalignment as seen by the optical lever. Around t = 30min it looks like a realignment attempt happened.
We don't want to cut out the DRMI offloading. When we locked DRMI we only actuate on M3 of PRM and SRM, but we need to offload to M2 to avoid saturating M3. So we need to figure out why the guardian is getting stuck there (maybe there is a hidden sleep some where). Another thing we could do is engage the wfs first and then offload; maybe that would be fine.
Also there haven't been any "new" decoupling filters installed in ETMX L2P L1 stage since Arnaud installed these (alog 11832). Jeff/Sheila/I had only been investing ETMY L2P more recently because that seemed to be the bigger issue.
This is a 5 hour trend with more advanced tools.