[Steve, Jenne, Yuta, Manasa]
We have kept the laser ON at low power through the pump down process. As we pumped down, at around 400torr, we found that the PSL mech shutter closed. Steve explained that it was due to an interlock with a pressure gauge. To keep the IFO running, we switched the shutter from N.C (normally close) to N.O (normally open). This should be undone after the pumpdown.
In the process of figuring out, we reset the shutter and switched it ON and OFF a couple of times. |