Sheila & Jeff B. Over the past few shifts the ALS green power build up in the X arm has steadfastly remained below 0.95 despite all tuning efforts. The Y arm build up as been normal. We trended the X Arm DC power. On the 24th the power of the green laser dropped from 1.02 to 0.95, (trend posted below).
[Travis, Jenne]
We tried chasing alignments a little bit, but also can't get the transmitted power above 0.95ish. Travis suggested looking at the laser itself. In the attached screenshot you can see that the green DC power measured at the end station dropped suddenly, at a time corresponding to the drop in transmitted power. Why would the power drop like that? Were there things going on at the end station around the 24th?