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Revision 367 as of 2019-01-11 14:17:35
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Revision 368 as of 2019-01-18 13:23:52
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Deletions are marked like this. Additions are marked like this.
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==== Report for week of 12/17 ==== ==== Report for week of 1/14 ====
 * Etc
  * Hirata-san ordered three 41 mm spanners for adjusting the jacks under the top of the tanks.
  * Mirapro installed bellows on the -Y side of BS and the +Y side of SR2.
  * Simon got us an LED, a 2D QPD stage and a second 300x400 mm breadboard, which should be enough to do the SRM TILT OL. He's working on a few more items needed for the LEN OL.
  * Terada-san and Uchiyama-san placed height markers on the SR tank frames showing the BS height and the desired SR heights allowing for 1/300 gradient: SR2 BS+17 mm, SR3 BS+56 mm, and SRM BS+70 mm.
  * Terrence and Mark reworked the Type B Guardian code to simplify future maintenance, so that the scripts `VIS_BS.py` etc are now tiny stub files which call common code in `TYPEB.py`.
  * Mark, Terrence and Enzo updated all the Type B models and MEDM screens to add support for binary output to the stepper driver enable inputs, and Enzo ran cables from the front ends to the BIO adapters, and thence to the drivers. We tested the SRM setup but it doesn't yet work.
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  * We opened the top of the BS tank after the vent.
  * We inspected the BS F0 blades for cracks but still didn't find any.
  * We removed the arc weights and geophones, and added new longer studs for the arc weights and new cables for the geophones. We then put back the original arc weights and new geophones.
  * We measured the geometry of the various IP items to check the IP diagonalization matrices.
  * We installed the new double-sided F0 FR. We were not close to needing to add the optional !CuBe spring. Unfortunately the FR had rather less friction but still didn't work. After checking a bunch of possibilities and comparing against SRM (also non-working) and SR2/SR3 (working), we suspect the carriage may be assembled upside down, with the metal plate below and the PEEK plate above. We will try changing it next week.
 * We adjusted the F0 keystone trim mass and were able to get it to sit at CAD nominal height at nominal temperature (24.9°C) with mid-range FR and modest extra mass (413 g). Interestingly, we noticed that removing the arc weights and/or geophones reduced the load capacity by a few hundred grams.
 * We measured the total range of the IP FRs in steps and set them to mid-range in preparation for tuning the IP frequency and (re-)centering the IP.
  * We installed the three new geophones originally prepared for SRM and then realized we'd made a serious mistake: the old wiring used adapters at both ends of the cable to compensate for the flipped preamps in the original geophones, and we forgot to take out the ones at the rack end. So two of the new ones appear to have been damaged and will have to be repaired. VIS has enough preamps to fix all the broken Type B geophones, but Type A will also need some more soon and there aren't enough in total, so we will have to repair them.
  * Hirata-san tried various things including turning the F0 FR carriage upside down to try to fix the jamming problem but it didn't seem to help. After advice from Takahashi-san and further debugging we discovered that we had a half-dead channel on the BS_GAS stepper driver, so we switched to a working channel, and that fixed things.
  * We recalibrated the F0 LVDT, this time measuring the height from the top down as we had been doing for the SRs. We also measured the range of the F0 FR in steps and millimeters and its effect on the keystone.
  * We tuned the IP for frequency and centered it in L, T and Y.
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  * We borrowed an LED from SR2 and set the pitch of the SRM optic.
  * We found the SRM front end had crashed and could not be properly reset by cycling the power from the web interface. Yamamoto-san eventually got it working for us, although it didn't seem to take more than restarting the user and IOP models.
  * We sealed and retested the new geophones originally intended for SRM, but decided to use them on BS instead.
  * We installed the two OL viewports. We also tried to install the camera viewport but we couldn't get the Cu gasket to sit in the recess, so we gave up and will probably reallocate the camera viewport to SR3 for now (where it will go on a different type of flange which we've had success with. Saito-san says that we can get help with the SRM flange from Mirapro on 1/28.
  * Hirata-san checked the F0 yaw stepper and it worked.
  * (CHECK!!) Hirata-san checked the channels on the SRM stepper drivers and found they all worked. However the F0 FR still didn't move, so he tried turning the carriage upside down, and that fixed it. So between the BS and SRM there were two independent causes of the same problem.
  * Fabian surveyed the height of the SRM relative to Terada-san's reference with the GAS filters at nominal height and found it was 3.5 mm low. This is well within the range of the jacks, so we will raise the entire suspension to fix it.
  * Fabian inspected the optic. It seems OK for dust, but there is still some residue left from removing the FC. We may try some more dabbing with acetone.
 * SR2
  * Terrence and Enzo tested the third and last type of collimator (3500 mm) in the OL, but it had much too small a spot and dynamic range. We will standardize on 1.1 mm collimators for all OLs.
  * Fabian inspected the optic and found patterns that may be FC residue on both sides.
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  * We opened the top of the tank briefly to inspect the configuration of the F0 FR, but didn't do any significant work.
  * Hirose-san inspected inside the bottom part of the chamber and found some dust, so he recommended we wipe with Vectra-Alpha wipes (IPA-resistant type) and IPA. he gave us a powerful LED flashlight array and asked us to use it to look for dust in all the chambers.
 * Etc
  * We gave Simon a list of items we still need for the SRM OL. He seemed to think that they should be in stock at Kamioka and will help us look for them next Tue 1/15.
  * Mark and Enzo booked flights for the KAGRA International Workshop.
  * Mark had to schedule a trip to Australia for the week of 1/21 to attend to family business.
  * Fabian and Ohishi-san tried using the Top Gun to remove dust found earlier by Hirose-san. The AR side came clean but the HR did not improve. Fabian wiped the security structure and LBB with Vectra10 wipes and ethanol.

==== Plan for week of 1/21 ====
 * Mark in Australia.
 *
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==== Plan for week of 1/7 ====
 * Make sure BS is floating, recenter OL to capture current yaw position.
 * Vent BS.
 * Inspect BS F0 blades for cracks.
 * Install new BS F0 FR, and (if necessary) auxiliary CuBe spring.
 * Confirm geometry of LVDTs, geophones, FRs etc and update T1707205 if necessary.
 * Replace geophone preamps and cables (to fix noise, offset, pinout flip issues).
 * Add more mass to IP to get lower frequency.
 * Adjust all GAS filters to near mid-range (using keystone mass for F0 as much as possible, and FR+LVDT for SF and BF).
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 * Hirata-san at Mitaka Thu 1/31, Fri 2/1.
 * Enzo at Mitaka Fri 2/8.
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 * Terrence: back at Kamioka from 1/7.  * Terrence at Kamioka till 3/29.

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 1/14

  • Etc
    • Hirata-san ordered three 41 mm spanners for adjusting the jacks under the top of the tanks.
    • Mirapro installed bellows on the -Y side of BS and the +Y side of SR2.
    • Simon got us an LED, a 2D QPD stage and a second 300x400 mm breadboard, which should be enough to do the SRM TILT OL. He's working on a few more items needed for the LEN OL.
    • Terada-san and Uchiyama-san placed height markers on the SR tank frames showing the BS height and the desired SR heights allowing for 1/300 gradient: SR2 BS+17 mm, SR3 BS+56 mm, and SRM BS+70 mm.
    • Terrence and Mark reworked the Type B Guardian code to simplify future maintenance, so that the scripts VIS_BS.py etc are now tiny stub files which call common code in TYPEB.py.

    • Mark, Terrence and Enzo updated all the Type B models and MEDM screens to add support for binary output to the stepper driver enable inputs, and Enzo ran cables from the front ends to the BIO adapters, and thence to the drivers. We tested the SRM setup but it doesn't yet work.
  • BS
    • We installed the three new geophones originally prepared for SRM and then realized we'd made a serious mistake: the old wiring used adapters at both ends of the cable to compensate for the flipped preamps in the original geophones, and we forgot to take out the ones at the rack end. So two of the new ones appear to have been damaged and will have to be repaired. VIS has enough preamps to fix all the broken Type B geophones, but Type A will also need some more soon and there aren't enough in total, so we will have to repair them.
    • Hirata-san tried various things including turning the F0 FR carriage upside down to try to fix the jamming problem but it didn't seem to help. After advice from Takahashi-san and further debugging we discovered that we had a half-dead channel on the BS_GAS stepper driver, so we switched to a working channel, and that fixed things.
    • We recalibrated the F0 LVDT, this time measuring the height from the top down as we had been doing for the SRs. We also measured the range of the F0 FR in steps and millimeters and its effect on the keystone.
    • We tuned the IP for frequency and centered it in L, T and Y.
  • SRM
    • Hirata-san checked the F0 yaw stepper and it worked.
    • (CHECK!!) Hirata-san checked the channels on the SRM stepper drivers and found they all worked. However the F0 FR still didn't move, so he tried turning the carriage upside down, and that fixed it. So between the BS and SRM there were two independent causes of the same problem.
    • Fabian surveyed the height of the SRM relative to Terada-san's reference with the GAS filters at nominal height and found it was 3.5 mm low. This is well within the range of the jacks, so we will raise the entire suspension to fix it.
    • Fabian inspected the optic. It seems OK for dust, but there is still some residue left from removing the FC. We may try some more dabbing with acetone.
  • SR2
    • Terrence and Enzo tested the third and last type of collimator (3500 mm) in the OL, but it had much too small a spot and dynamic range. We will standardize on 1.1 mm collimators for all OLs.
    • Fabian inspected the optic and found patterns that may be FC residue on both sides.
  • SR3
    • Fabian and Ohishi-san tried using the Top Gun to remove dust found earlier by Hirose-san. The AR side came clean but the HR did not improve. Fabian wiped the security structure and LBB with Vectra10 wipes and ethanol.

Plan for week of 1/21

  • Mark in Australia.

To-Do Lists, Schedule

Vacation/Etc Info

  • Hirata-san at Mitaka Thu 1/31, Fri 2/1.
  • Enzo at Mitaka Fri 2/8.
  • Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.
  • Terrence at Kamioka till 3/29.

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-10-28 10:02:46 by fabian.arellano)