KAGRA VIS Meeting
2015/8/5 15:00 - 17:00
First Meeting Room of NAOJ
TV conference: 188.8.131.52
SeeVogh: KAGRA VIS
Shoda, Hirata, Sekiguchi, Fujii, Tatsumi, Mark, Fabian, Akutsu, Ohishi
- Currently in the schedule chart, 5 weeks for the in-air assembly (including cabling) + 1 week for in-air tuning is assigned.
- Mechanical assembly and cabling will take place alternately.
Let me (Aso) know if you have suggestions about the schedule
Uchiyama-san's slides http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3866
- Installation Review
- We should have a review meeting on the whole installation procedure of Type-Bp suspension early next week
- Aso will circulate a Doodle poll
- The meeting should be about glueing (Tatsumi), IM assembly (Shoda), mirror hanging (Fabian's document), and everything else (Mark).
- Payload test hanging at Mitaka
- We may want to do it in the clean room for BF assembly.
- Put a bread board on a table there ? Using shims to level the bread board ?
- Spare mirror glueing will finish on 8/19. The test assembly can start on 8/24 ?
Shoda-san will take charge of this with help from Fabian and students.
- Current status
- Alignment control of the prototype suspension with an optical lever was successful. But not so stable.
RM pitch mode around 5Hz is a problem. Could use the RM magnetic damper -> Sekiguchi-kun will try it.
- Changing the RM wire to thin ones will reduce the resonant frequency of the pitch which makes the control even more difficult.
- We probably need to keep using Tungsten wires (higher elestic constant).
- We should buy Tungsten wires with several different diameters and try winding with winches to determine the thickness of the wires (thickest possible one).
Shoda-san will buy Tungsten wires after consulting with Takahashi-san.
Preparation status of the iKAGRA large suspensions
Review of the cabling plan made by Mark should take place in this week at Mitaka.
- Waiting for parts to arrive: Expected delivery Aug. 23rd. Assebly and calibration will follow. OSEMs will be ready early September.
- Satellite box: Talking with AEL group about current limiting resistor.
- Got a high power coil driver from AEL
Tyep-Bp temporary damper
- Simulation by Soda-san
- Adding OSEMs on the BF to actively damp it seems the best solution
Need to check the required force to damp the suspension (Shoda)
- Fixing the BF to the traverser is another option. It has performance degradation.
- Feasibility check of the modifications by Mark
- Easiest one seems rigidly connecting the bottom filter to the traverser.
- Adding OSEMs are relatively easy. However, moving range of the BF for alignment will be severely limited by the exisitence of the OSEMs.
- If we use reflective photo-sensors instead of OSEM, we may be able to increase the adjustment range ?
- What to do for the temporary damper
- Option 1: Do nothing. We may be able to lock iKAGRA with 5um/sec RMS. Need more considerations.
- Option 2: Do the imobilization of the BF for iKAGRA. Change it to a better one for bKAGRA if necessary.
- Option 3: Add OSEMs to the BF if we come up with a good idea to keep the adjustment range of the BF.
We should decide on the strategy by the next VIS meeting