• KAGRA
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• TypeB
• Minutes

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for the week of 2/18 (February 18th)

• On Friday and Saturday last week the pump down of the central area took place. We monitored the drift in the four Type B IPs.
• During the week we recovered the four suspensions successfully: we recovered the alignment of IMs, GAS filters, IPs, oplevs and measured TFs.
• Terrence, Enzo and Mark installed the length sensing components in SR2 oplev. It's working now and we should use it now to measure the optic's corresponding TF.

• The SRM IM is still drifting but the speed is decreasing. Yesterday Thursday the speed was -81 nrad/min. With the aim of predicting when the drift may stop Terrece removed offsets from the time series segments and spliced them in order. The work is still on progress.

• Terrence did more work in changing the real-time models.

Report for week of 2/12 (February 12th)

• On Saturday we moved the vertical IM OSEMs in order to compensate for a large pitch in the IM introduced when the IR laser as aligned.
  • I took transfer functions over the weekend and the system looks healthy.
  • Although moving the OSEMs was done successfully, I accidentally pulled the cables and moved the flying saucer cable clamp set. I rotated it back judging the position by visual inspection, but an IM yaw drift appeared since then. It's moving with a speed of 0.2 urad/min.
  • On Tuesday we moved the Im back to zero but the drift continued. At the time of writing these lines it is at -833 urad, with H2 and H3 at 93 um and 47 um and still drifting.
• On Saturday we connected the SRM geophones in-air cables and confirmed we had a signal.
  • However, on Wednesday morning the geophones are not giving any signal. We cheked the master model channel and realized the problem was not the slave model. We suspect a hardware fault.
  • I checked the in-air cables were connected.
• We released the SRM optical bench and wiped the places where sticky tape was used to fix support blocks.
• We wiped the SR2 optical bench and security structure. SR3 and SRM had been wiped by Hirose-san, Hirata-san and Fujii-kun.
• Terrence worked on splitting the real-time models for all the SR suspensions.
• Today the pumping down of the central area will begin around noon. We will monitor the four inverted pendulums
• We got rid of the cable reel used in the SR2 rack.

Report for week of 1/28

• Etc

  • Mark inventoried lots of items and updated the Status page.

• SR2
  • Hirata-san helped with installing the obelisk on the LBB, and added counterweights to get the LBB level and at the right height for the first rough alignment. However the springs were still at or near the top stops, so he later pulled down the LBB with excess mass, locked the blades at the bottom of their range and reset the LBB rods and damping magnet ring, aiming off by 10 mm so that it would be correct when the LBB was allowed to rise to midrange on the blades. He left it pressed down for now so that Hirose-san could apply FC. Early next week he will release it and do the final ballasting.
  • Hirose-san applied and removed FC on both sides of the optic for cleanliness.
  • Mirapro hooked the LBB.
• SR3
  • Enzo installed IM damping filters.
  • Mark installed a BIO Converter for the stepper remote enable (which will eventually also be used for the WD).
  • Fabian researched buoyancy compensation and pre-applied as much as possible to SR3. The total compensation needed is 0.19 mm for F0, 0.48 mm for SF and 0.46 mm for BF, total 1.23 mm. 1.0 mm had been applied with the jacks. The initial plan was to apply the calculated amounts at each level but then offset F0 1.0 mm lower to undo the jack adjustment. However SF was stuck approximately 1 mm lower than it needed to end up, so the buoyancy correction for it will have to be done at F0, and F0 will end up quite close to nominal.
• Fabian also offloaded the IM pico yaw adjustment done by Enomoto-kun-tachi to the F0 yaw stepper. This left the OSEMs well-centered, so we will not need to adjust them and the LBB can be released.
• SRM
  • Enzo fixed the broken triple in-air pico adapter cable and we plugged it back in.
  • Fabian calibrated the F0 FR.
  • Enzo and Terrence installed the arc weights and geophones, tuned and centered the IP, and centered and calibrated the FRs.
  • Mirapro helped us with the camera viewport issue by giving us a gasket of the same type but a different brand from their stock, which snapped easily into place. We then installed the viewport on the tank. Kokeyama-san will help us add the camera and camera LAN cable next week.
  • Simon gave us all the remaining items for the SRM OL except the 3D stage for the LEN QPD.

Plan for week of 2/4

• Mark, Enzo, Fabian, Terrence at Kamioka Mon-Fri.
• Hirata-san at Kamioka Mon+TBD.
• Etc
  • Split SR2, SR3 and SRM RT models.
  • Get rid of the power reel behind SRM and plug stuff into the new power point instead.
• BS
  • Run BNC cables for stepper remote enable, plug into BIO, debug.
• SR2
  • Do buoyancy correction.
  • Install camera viewport.
  • Install camera.
  • Run BNC cables for stepper remote enable, plug into BIO, debug.
• SR3
  • Release LBB.
  • Ballast LBB.
  • Install camera viewport.
  • Install camera.
  • Debug stepper remote enable.
• SRM
  • Install camera.
  • Ballast LBB.
  • Do buoyancy correction.
  • Set up OL.
  • Debug stepper remote enable.

Vacation/Travel Info

• Constitution Day, 2/11.
• Mark and Enzo at KIW in Perugia, 2/12-18.
• Enzo vacation, 3/5.
• Enzo et al. Farewell Party, 3/7.
• Enzo at JPS then final vacation, 3/13-29
• Terrence's last day, 3/29.