Scraps of text for incorporation in the VIS Meeting Minutes
Type B (Mark)
Report for the week of 3/18
- Terrence notice that one of the IP LVDTs was not working. We traced it to an unplugged cable, plugged it back in and screwed it together to prevent a recurrence.
- Simon helped us rebuild the damaged LEN OL QPD stage and Terrence reinstalled it. We removed a C-clamp that we had been using to immobilize the breadboard because it interfered with the QPD stage, and replaced it with a more elegant solution using a dog clamp underneath.
- We noticed that the BS IP had fallen over in +L at some time shortly before Nakano-san aligned the optic on 3/18. Terrence tried to recenter it but it was unstable. We decided to remove the tank lid one more time and remove some arc weights. The IP frequency had been 39 mHz the last time it was measurable, and we increased it to a much-safer 80 mHz by removing 9 kg. We believe we were able to recover Nakano-san's alignment fairly closely.
- Terrence then recalibrated and diagonalized both the TILT and LEN OL.
- Terrence recalibrated the OL.
- Mark pulled out unused cables leading into the SR3 cleanbooth.
- Terrence set up the SRM Guardian.
- Mark did an audit of the OL whitening/dewhitening system and fixed a bunch of problems: the SRM chassis was the wrong type, with no actual whitening card; SR2 and SRM needed whitening filters turned on; BS LEN needed the dewhitening turned on; SR2, SR3 and SRM needed dewhitening filters installed and turned on; SRM needed more gain.
- Terrence weeded out a minor error from his OL diagonalization scheme and got L, T and Y independent at the 1% level for SR2 and SRM. He will do SR3 next.
- Fabian measured the gain resistor values and other settings of the LVDT drivers, in case a card or chassis fails and we have to approximate the original state without the chance to recalibrate from scratch.
- Fabian monitored the pumpdown.
Plan for week of 3/25
- Mark, Fabian, Terrence at Kamioka Mon-Thu.
- Assist with alignment.
- Work on Type B paper.
- Tidy up.
- Throw out foil and other garbage.
- Gather and clean tools.
- Gather and organize unused parts and fasteners.
- Return all unused cables to tent.
- Tidy up cables in rear of SR2 rack.
- Enzo's final vacation till 3/29.
- Terrence's last day for now, 3/29.
- Mark compensation day for 3/21: 3/29.
- Type B going-away party for Terrence/Enzo, 3/29 in Tokyo.
- Terrence's next visit from 4/18.
- Fabian's vacation 4/26 to 5/10.
- Mark's final day ≈6/28 (TBD).