Differences between revisions 367 and 417 (spanning 50 versions)

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for Golden Week

Mark monitored vent and pumpdown, and worked on vistools.py.

Report for the week of 5/6

Lucia and Terrence got the blending working for the IP LVDTs and geophones.
Terrence and Mark modified the models and MEDM screens to add a new IP block, IDAMP, for damping using the blended signal with inertial information, and a new DAMPMODE block for ramping smoothly between IDAMP and the old DAMP.
Mark worked on vistools.py, improving the support for cdsMuxMatrix blocks (e.g., OSEM2EUL) and adding support for cdsRampMuxMatrix blocks (e.g., the newly introduced DAMPMODE). He also created two sets of unit tests, unittest.py and unittest.sh, for the two modes of use (as a Python module in other Python programs, and as a command-line utility in bash).

Report for week of 5/13

Terrence measured Q's for nearly all modes on SR2 from TFs and then did some ring-down tests to get a better estimate of some high-Q modes.
Terrence and Mark looked at the velocity and angular velocity noise of the SR2 as reported by the LEN and TILT OLs.
- The Y signal was fairly clean and the Y RMS angular velocity requirement was met. However the L signal was quite noisy, and was also contaminating the P signal due to the large cross terms in the diagonalization matrix. The RMS L from 5 Hz down with damping on was around 10 µm/s, which is 10 times the requirement. However little of this was due to pendulum resonances - most of the noise was featureless and broadband. In displacement units the noise was flat up to about 1 Hz and then smoothly rolled off to f^-2. The noise in the raw P and Y signals (not yet divided by the sum) was about 10 times the noise in the SUM.
- We tried improving the noise with different whitening settings. Increasing the overall gain, increasing it at the QPD but reducing it at the whitening filter, and switching off the 1-10Hz boost whitening filter (and compensating software filter) had no effect. Blocking the beam reduced the noise by about 2 orders and brought the raw P and Y in line with the SUM, suggesting that the problem was before the QPD. Akutsu-san says the noise spectrum looks like it may be limited by air currents, and we probably need better wind shielding.
Mark swapped in an improved version of vistools.py, debugged a few small issues, and simplified the TYPEB.py Guardian.
Fabian embarked on a project to calculate the residual motion within KAGRA's observation band (beginning at 10 Hz) to make sure The Type B suspension fulfills the requirement, and calculate the speed of the optic to make sure we can acquire the lock.
- He modified Takanori's Simulink/Matlab simulation in order to include the length sensing oplev and its control feedback path.
- He imported Enzo's IM/GAS/IP-LVDT filters into the simulation.
- He imported into the simulation the measured LVDT floor noise (sensitivities).
- He calculated the IP-L, IP-T and IP-Y sensitivities.

Plan for week of 5/20

Mark at Mitaka Mon, Tue; US from Wed till 6/11.
Fabian
- Import Panwei's OSEM sensitivity measurements and calculate the sensitivity of the virtual IM sensors.
- Import geophones sensitivities and calculate the sensitivity of the corresponding virtual sensors.
- Import Licia's and Terrence's inertial sensing filters.
Terrence
- Try to reduce the OL noise and get better estimates of the RMS velocity with damping on.

Vacation/Travel Info

Terrence's next visit from 4/18 to 7/27.
Mark's US vacation from 5/22 to 6/11.
Fabian at conference in Brazil from 5/31 to 6/17.
Mark's final day 6/28.

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

-  ⇤ ← Revision 367 as of 2019-01-11 14:17:35 → 
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+   ← Revision 417 as of 2019-05-17 13:38:34 → ⇥
  Size: 3817
  Editor: MarkBarton
  Comment:
-Deletions are marked like this.
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-==== Report for week of 12/17 ====
 * BS
  * 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.
 * SRM
  * 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.
 * SR3
  * 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.
==== To-Do Lists, Schedule ====
 * [[KAGRA/Subgroups/VIS/TypeB/ToDoBS]]
 * [[KAGRA/Subgroups/VIS/TypeB/ToDoSR]]
 * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7779|JGW-L1807779 Type B Schedule (SR)]]
+==== Report for Golden Week ====
 * Mark monitored vent and pumpdown, and worked on vistools.py.
-Line 32:
+Line 8:
-==== 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).
+==== Report for the week of 5/6 ====
 * Lucia and Terrence got the blending working for the IP LVDTs and geophones.
 * Terrence and Mark modified the models and MEDM screens to add a new IP block, IDAMP, for damping using the blended signal with inertial information, and a new DAMPMODE block for ramping smoothly between IDAMP and the old DAMP.
 * Mark worked on vistools.py, improving the support for cdsMuxMatrix blocks (e.g., OSEM2EUL) and adding support for cdsRampMuxMatrix blocks (e.g., the newly introduced DAMPMODE). He also created two sets of unit tests, unittest.py and unittest.sh, for the two modes of use (as a Python module in other Python programs, and as a command-line utility in bash).
-Line 42:
+Line 13:
-==== Vacation/Etc Info ====
 * Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.
 * Terrence: back at Kamioka from 1/7.
+==== Report for week of 5/13 ====
 * Terrence measured Q's for nearly all modes on SR2 from TFs and then did some ring-down tests to get a better estimate of some high-Q modes.
 * Terrence and Mark looked at the velocity and angular velocity noise of the SR2 as reported by the LEN and TILT OLs. 
  * The Y signal was fairly clean and the Y RMS angular velocity requirement was met. However the L signal was quite noisy, and was also contaminating the P signal due to the large cross terms in the diagonalization matrix. The RMS L from 5 Hz down with damping on was around 10 µm/s, which is 10 times the requirement. However little of this was due to pendulum resonances - most of the noise was featureless and broadband. In displacement units the noise was flat up to about 1 Hz and then smoothly rolled off to f^-2. The noise in the raw P and Y signals (not yet divided by the sum) was about 10 times the noise in the SUM.
  * We tried improving the noise with different whitening settings. Increasing the overall gain, increasing it at the QPD but reducing it at the whitening filter, and switching off the 1-10Hz boost whitening filter (and compensating software filter) had no effect. Blocking the beam reduced the noise by about 2 orders and brought the raw P and Y in line with the SUM, suggesting that the problem was before the QPD. Akutsu-san says the noise spectrum looks like it may be limited by air currents, and we probably need better wind shielding. 
 * Mark swapped in an improved version of `vistools.py`, debugged a few small issues, and simplified the `TYPEB.py` Guardian.
 * Fabian embarked on a project to calculate the residual motion within KAGRA's observation band (beginning at 10 Hz) to make sure The Type B suspension fulfills the requirement, and calculate the speed of the optic to make sure we can acquire the lock.
  * He modified Takanori's Simulink/Matlab simulation in order to include the length sensing oplev and its control feedback path.
  * He imported Enzo's IM/GAS/IP-LVDT filters into the simulation.
  * He imported into the simulation the measured LVDT floor noise (sensitivities).
  * He calculated the IP-L, IP-T and IP-Y sensitivities.

==== Plan for week of 5/20 ====
 * Mark at Mitaka Mon, Tue; US from Wed till 6/11.
 * Fabian
  * Import Panwei's OSEM sensitivity measurements and calculate the sensitivity of the virtual IM sensors.
  * Import geophones sensitivities and calculate the sensitivity of the corresponding virtual sensors.
  * Import Licia's and Terrence's inertial sensing filters.
 * Terrence
  * Try to reduce the OL noise and get better estimates of the RMS velocity with damping on.

==== Vacation/Travel Info ====
 * Terrence's next visit from 4/18 to 7/27.
 * Mark's US vacation from 5/22 to 6/11.
 * Fabian at conference in Brazil from 5/31 to 6/17.
 * Mark's final day 6/28.