The laser tripped this morning. The status screen red flagged the following:
- Xtak chiller flow
- Interlock OK
- Frontend Power error (WD)
- Oscillator Power error (WD)
Initial thought was that a water leak occurred. That was not the case.
Suspect that the power watchdog was tripped because the injection locking was lost.
When the injection locking servo loses lock, the laser power drops and sets off the
watchdog.
The laser restarted without any problems, other than the alignment into the pre-modecleaner
was off a little. Upon recovery, the pre-modecleaner had some problems locking. Went into the
PSL Enclosure to adjust the alignment but by the time we got inside, the pre-modecleaner was locked.
Tweaked the alignment a little.
Closed the other loops successfully. After deliberately bringing up and down the input
modecleaner a couple of times, the FSS seemed fine with the occasional PZT oscillation.
JeffB/Ed/Peter
Before the alignment tweak the output of the locking photodiode was ... - unlocked -1.017 to -1.024 V - locked -0.148 -0.161 mV This corresponds to a visibility of ~85%. After the alignment tweak ... - unlocked -1.017 to -1.024 V - locked -0.142 mV to -0.155 mV This corresponds to a visibility of ~86%.