20180301
Today's activities
Workers: Simon, Miyo, Akutsu
- Checked and identified each thermometer on the WAB and the suspension.
- First fixed the WAB again.
Dhecked whether their thermal contacts were nice. Seemed are.
- Each thermometer was fixed with a M3 short screw, the washer, and the spring washer.
- Checked several screws, taking advantage of the fixed state of the WAB.
M5 nuts to tighten the heat links to the WAB. It was a hard work as the space was too narrow...
- Heaters.
Lowered the WAB to the nominal position at the room temperature; details here.
- First stood a vertical ruler and illuminated it with a laser leveler that was shooting the center of the WAB in the vertical direction.
- Then lowered the laser lever by 2mm.
- Loosened M3 screws on the top of the suspension, then rotated three vertical adjusters there, and then tightened the M3 screws.
- The vertical adjusters were rotated in a single counterclock wise to lower the WAB while the WAB was fixed; meaning the vertical springs were slightly loosened at that time.
- Removed the protectors so that the WAB was suspended/floating again.
- As foreseen (not wanted), one of the vertical spring said "beeeeeen" slightly but other than that, no big issues happened, fortunately.
Confirmed the again suspended WAB's center line was consistent with the laser leveler's illuminating line! WE DID IT!
- Actually we should not/need not to do this work for the actual integration procedure of the WAB; it should be suspended in the position of the room-temperature nominal position. Otherwise it would be dangerous to do this kind of work with an actual sapphire mirror will be there...
- Reset relative positions of photosensors; Simon measured/set each 18mm.
- Will increase to 20mm gap in the Z direction when it will be cooled down.
Found the optimal amount of the current to the coil in the current situation.
- Because the distance between the coil actuator and the magnet on the WAB got close, the 1A would be too large.
- Found 0.5A was sufficient. Less would work.
[Ongoing] Need cares of water springs from anchor bolts for oplev pylons.
[Ongoing] Need to confirm what are the scratch lines made by the measurement by the KEK team last week.
Next plan
- Make heat connection upper and lower part of the suspension by Cu wires.
- Make heat anchors for some electric wires in which large current will flow.
- Optimize the current amount to the coil.
- Complete the PS calibration.
- Complete the calibration of the oplev; the arm length was reported by Simon, so....
- Complete the signal matrix.
- Check the balance of the suspended WAB with some wires and sensors are attached.
- Check how the damping would be now after the replacement of the damping magnets.
- Check the reproducibility of the alignment of the suspension among several modes.
- Check heights of several points.
- Take care of water spring??
Wanted!
- Two burndy connectors, vacuum compatible.
Stages outside the chamber to ease wiping our legs.
Good rail(?) to move the WAB suspension in the cryostat in the main beam direction.
Chain block? to support the load in the chamber.
- A clock to know the time easily.
- M6 screw set.