Differences between revisions 375 and 404 (spanning 29 versions)
⇤ ← Revision 375 as of 2019-01-25 09:20:41 →
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Editor: fabian.arellano
Comment:
← Revision 404 as of 2019-03-15 13:35:48 → ⇥
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Editor: MarkBarton
Comment:
Deletions are marked like this. Additions are marked like this.
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==== 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. We got 78 mHz.
 * 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.		 ==== Report for the week of 3/11 ====
 * Fabian helped Fujii-kun with the PRM most of the week. Hirata-san also helped at various times.
 * Fabian monitored the SRM yaw drift. It gradually reversed but so far remained small. We will try resetting it to zero with the pico and see if the trend changes.
 * Mark and Hirata-san debugged the BS:
  * We inspected the payload section and quickly found the problem: two RM EQ stops were touching, on the +L (-X,+Y) side at the top. This was probably because the stops had been adjusted with the IP unlocked and sitting a few mm to -L, whereas now we have the DCCTRL running and have been locking the IP at the LVDT zero. We drove the IP to L=+1.5 mm as a near-worst case, and backed off all the stops to give several mm of margin. Then we zeroed the IP pitch, roll and yaw with the picos.
  * We also opened the top of the BS and confirmed that the mechanical zero defined by the locking mechanism agreed with the LVDT zero. It was very close in L and T, but -728 µrad in Y, driven mostly by a -805 µm offset in H3. That much is probably not a dumb error but just a difference in technique among the three people using calipers to take data for the calibration.
  * We then prepared the BS for close-up:
   * We wiped and inspected the O-ring for the lid and replaced the lid.
   * We wiped all accessible surfaces in the lower half of the tank, rescued some dropped items (some PEEK tube and a small nut) and un-immobilized the LBB.
  * After all the above, the OL was a bit off-center but still on the QPD, and Nagano-san fairly quickly recovered the original alignment.
 * Terrence rebuilt the BS TILT OL according to a new layout suggested by Simon, which avoids scrambling the pitch/yaw at the first steering mirror and greatly reduces the amount of diagonalization required. He started on the LEN OL, but unfortunately the QPD stage fell and bent the brackets holding two of the micrometers. It's useable but we haven't installed it yet.
 * Terrence noticed some anomalous cross coupling on the SR2 (but not the SR3) and we investigated.
  * We suspected it might be an odd position of the beam spot on the optic, so we took pictures through the camera and LED viewports of SR3, and opened the SR2 tank and used a white target, but the beam spots were in very similar positions - close to central vertically and about 3 cm to the left of center horizontally.
  * We suspected it might be something touching at the IRM (because the IM OSEM TFs were fine), so we checked using a stick mirror with the IP centered, but all EQ stops were well backed off.
  * We suspected it might be a ghost beam from the LEN/TILT beamsplitter (and one was clearly visible on the SR2 TILT QPD) so Terrence set up a beam block, which improved things slightly but not completely.
  * Finally Terrence discovered that the problem was mainly uneven sensitivities of the QPD quadrants, and devised a new calibration procedure which allowed for it. Later we discovered that one of the 3 dB gain stages on the whitening filter was engaged, even though the switch on the BIO Config card was not. It mysteriously came good after we removed and replugged the card.
 * Enzo and Terrence did a health check of the SRM and it was fine except for some apparent electrical noise around 240 Hz. They put in a notch filter to get rid of it for now.
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==== Report for week of 1/21 ====
==== BS (top priority) ====
 * Last Friday: We tuned the IP to have a lower frequency. At the begginig we measured 78mHz.
 * Last Friday: With Lucia, we centered the IP and diagonalized the IP. After this process we measured a resonant frequency of 40mHz. We closed the position control loop for the IP.
 * We checked during the weekend and the suspension was not in a healthy state. We checked the IM horizontal OSEM coil driver, and there were some cables in the wrong connectors. (Test in instead of ...)
 * The adapter for the cable of the F0 fishing rod was not healtly. We fixed it but it might be good to replace it.
 * The commissioning team steered the BS IM to reach the Y-end and then Terrence centered the oplev with this orientation (more than once).
 * Fujii-san and Enzo fixed old BS geophones by replacing the Preamp.
 * We replaced the Geophones for the recently fixed ones. '''(This has not happened yet.)'''
 * Hirata-san and Fabian secured trim masses to the keystone. '''(This has not happened yet.)'''
 * We installed GAS Filters and IM control loops.		 ==== Plan for week of 3/18 ====
 * Mark, Fabian, Terrence at Kamioka full week.
 * More OL stuff.
 * SRM controls and Guardian.
 * Reset SRM yaw and continue monitoring yaw drift.
 * Assist with pump down.
 * Work on Type B paper.
 * Tidy up.
  * Throw out foil and other garbage.
  * Gather and clean tools.
  * Gather and organize unused parts and fasteners.
  * Pull out unused cables in cable tray near SR3.
  * Return all unused cables to tent.
  * Tidy up cables in rear of SR2 rack.
  *
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==== SR2 (priority 2) ====
 * We measured the optic height. According to the measurement it was 0.1 mm off. However, the systematic error is likely larger (laser level, position of reference). Apparently, the RM has a small amount of roll but this should be investigated further. It might just be systemaric error of the measurement. The roll of IM was adjusted to a value close to zero before the measurement.
 * We calibrated the F0 fishing rod stepper motor.
 * We raised suspension using the jacks. We rotated the jacks by 180 degrees roughly.Compensation has to happen with F0, F1 and BF.
 * We removed tape, writing etc on PI and PI items.
 * We removed the trim mass.
 * '''What did Terrence did for the oplev? '''
 * We centered the IP by using the Horizontal stepper motors. '''(This has not happened yet).'''
 * We diagonalized the IP actuation matrix. We closed the position control loop for the IP. '''(This has not happened yet).'''
 * We installed GAS Filters and IM control loops. '''(This has not happened yet).'''
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==== SR3 (priority 2) ====
 * The bouyancy correction was calculated. It's 1.3 mm.
 * The strategy is rasing the suspension by 1.3 mm and then moving the keystone by 1.3 mm with the fishing rod so the alignment team can work.
 * We measured the optic height using Terada-san's reference. The SR2 optic was at the correct height.
 * We raised suspension using the jacks by an amount calculated with the jack thread: M42 with 2 mm special thread. We rotated the jacks by approximately 180 degrees.
 * Terrence reinstalled OL LED, replaced the collimator and relaigned the OL. '''(What collimator did he installed?)'''
 * We removed tape, writing etc on PI and PI items.
 * We calibrated the F0 FR against the readout of the F0 LVDT. We removed the trim masses (110 g). Then we moved the F0 keystone by 1.3 mm downwards.
 * We centered the IP by adjusting the height of the jacks by small amounts. Longitudinal and Transverse positions came good but there was a large yaw (-5 mrad) when the stepper motors were in mid-range. Currently the yaw is -1 mrad and the steppers are using 80% of their range already.
 * The F0 yaw stepper should, in principle, give plus minus 125 mrad range. We should check with a measurement how good this range is (e.g. cables being pulled, components touching, etc.) We can use the vertical laser level as an oplev or the main interferometer beam.
 * '''F1 fishing rod is not responsive. We have to check the cables.'''
 * We diagonalized the IP actuation matrix. We closed the position control loop for the IP. '''(This has not happened yet).'''
 * We installed GAS Filters and IM control loops. '''(This has not happened yet).'''
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==== SRM (low priority) ====
 * Hirose-san, Hirata-san and Fujji-san fixed the RM to the SS and removed the SRM for cleaning.

==== Postponed ====
 * Raise suspension 3.5 mm on jacks.
 * Check/improve payload alignment and IM OSEMs. Recheck optic pitch with OL as needed.\
 * Adjust F0 keystone trim to give desired height and secure weights in place.
 * Install geophones and arc weights.
 * Center and tune IP.
 * Hook LBB and add just enough ballast to have it bouncing.
 * Wipe inside tank with Vectra-Alpha wipes and IPA.
 * Set up TILT OL.		 ==== Vacation/Travel Info ====
 * Enzo at JPS then final vacation, 3/13-29
 * Terrence's last day, 3/29.

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for the week of 3/11

  • Fabian helped Fujii-kun with the PRM most of the week. Hirata-san also helped at various times.
  • Fabian monitored the SRM yaw drift. It gradually reversed but so far remained small. We will try resetting it to zero with the pico and see if the trend changes.
  • Mark and Hirata-san debugged the BS:
    • We inspected the payload section and quickly found the problem: two RM EQ stops were touching, on the +L (-X,+Y) side at the top. This was probably because the stops had been adjusted with the IP unlocked and sitting a few mm to -L, whereas now we have the DCCTRL running and have been locking the IP at the LVDT zero. We drove the IP to L=+1.5 mm as a near-worst case, and backed off all the stops to give several mm of margin. Then we zeroed the IP pitch, roll and yaw with the picos.
    • We also opened the top of the BS and confirmed that the mechanical zero defined by the locking mechanism agreed with the LVDT zero. It was very close in L and T, but -728 µrad in Y, driven mostly by a -805 µm offset in H3. That much is probably not a dumb error but just a difference in technique among the three people using calipers to take data for the calibration.
    • We then prepared the BS for close-up:
      • We wiped and inspected the O-ring for the lid and replaced the lid.
      • We wiped all accessible surfaces in the lower half of the tank, rescued some dropped items (some PEEK tube and a small nut) and un-immobilized the LBB.
    • After all the above, the OL was a bit off-center but still on the QPD, and Nagano-san fairly quickly recovered the original alignment.
  • Terrence rebuilt the BS TILT OL according to a new layout suggested by Simon, which avoids scrambling the pitch/yaw at the first steering mirror and greatly reduces the amount of diagonalization required. He started on the LEN OL, but unfortunately the QPD stage fell and bent the brackets holding two of the micrometers. It's useable but we haven't installed it yet.
  • Terrence noticed some anomalous cross coupling on the SR2 (but not the SR3) and we investigated.
    • We suspected it might be an odd position of the beam spot on the optic, so we took pictures through the camera and LED viewports of SR3, and opened the SR2 tank and used a white target, but the beam spots were in very similar positions - close to central vertically and about 3 cm to the left of center horizontally.
    • We suspected it might be something touching at the IRM (because the IM OSEM TFs were fine), so we checked using a stick mirror with the IP centered, but all EQ stops were well backed off.
    • We suspected it might be a ghost beam from the LEN/TILT beamsplitter (and one was clearly visible on the SR2 TILT QPD) so Terrence set up a beam block, which improved things slightly but not completely.
    • Finally Terrence discovered that the problem was mainly uneven sensitivities of the QPD quadrants, and devised a new calibration procedure which allowed for it. Later we discovered that one of the 3 dB gain stages on the whitening filter was engaged, even though the switch on the BIO Config card was not. It mysteriously came good after we removed and replugged the card.
  • Enzo and Terrence did a health check of the SRM and it was fine except for some apparent electrical noise around 240 Hz. They put in a notch filter to get rid of it for now.

Plan for week of 3/18

  • Mark, Fabian, Terrence at Kamioka full week.
  • More OL stuff.
  • SRM controls and Guardian.
  • Reset SRM yaw and continue monitoring yaw drift.
  • Assist with pump down.
  • Work on Type B paper.
  • Tidy up.
    • Throw out foil and other garbage.
    • Gather and clean tools.
    • Gather and organize unused parts and fasteners.
    • Pull out unused cables in cable tray near SR3.
    • Return all unused cables to tent.
    • Tidy up cables in rear of SR2 rack.

Vacation/Travel Info

  • Enzo at JPS then final vacation, 3/13-29
  • Terrence's last day, 3/29.

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