J. Oberling, J. Bartlett, P. King (from Pasadena)

Jeff came in this morning and found the PSL to be off.  Trends indicated the laser turned off at around 3:25 am PDT, with errors showing the flow was zero and the NPRO was turned off (no power watchdogs were tripped); the crystal chiller was found to be off, while the diode chiller was still running.  The crystal chiller was restarted and allowed to run for ~15 minutes and no glitches or errors were seen (last time we had a flow problem the chiller would glitch when just running by itself, no laser).

In discussion with Peter he suggested the possibility of the NPRO tripping (likely due to a power glitch or a glitch from the UPS).  When this happens the NPRO power supply, located in the PSL rack in the LVEA, needs to be manually re-enabled.  Upon inspection, the NPRO power supply indeed had to be manually re-enabled, which points to either a power glitch or a glitch of the UPS the NPRO is plugged into.  We don't think it's a power glitch as that would cause issues with other IFO systems, and this was not seen.  This leaves the most likely culprit at this time as a glitch from the NPRO UPS.

The laser is now back up and running, all stabilization systems enabled.  I took this opportunity to reset the HPO LRA back to its reference position and reset the relock counter for the injection locking system.