The following report has been submitted to the On-call interface.
On-call events -> Interferometer Sensing & Control
Title: Problem with green locking at WE
Author(s): spinicelli
Called at: 10:00, 01-02-2025, by: Berni |
Remote intervention: Started: 10:00, 01-02-2025; Ended: 11:00, 01-02-2025 |
On-site intervention: Started: ; Ended: |
Status: Resolved |
Operator when issue resolved: Berni |
Details:
After un unlock of the ITF (07:59:38, reason unclear, it seems a glitch on INJ_EOM) the green at WE couldn't relock properly. Because of a misaligned BPC there was almost no green power on reflection; unfortunately, this has been recognized by the automation as arm locked since the locking trigger ( WEB_PD_REFL ) had the similar level as the one locked (fig. 1). The lock acquisition continued towards the beating step, failing at each time.
Indeed, after the unlock, SWEB controls opened, and even if the BPC at WE was engaged, it didn't recover the correct position (see fig. 2).
Opening and closing the BPC via VPM solved the problem.
The ITF is now relocking.
* Note that any files attached to this report are available in the On-call interface.