= Agenda/Minutes of the VIS Meeting on 2019/9/6 =
2019/9/6 15:00 - 17:00

[[https://zoom.us/j/203743987|Zoom Meeting]]

Participants: Hirata, Ishizaki, Shoda, Takahashi, Aso, Fujii, Lucia, Fabian, Okutomi, Akutsu, Tanaka

== Progress report ==
=== Type-A ===
==== Past week report ====
 * Updated the list of the modification parts in the 3D CAD model.
 * With Miyo-kun, we implemented sensor correction filter to IP-LVDT using the following sensors:
  * local seismometers on ground at EXV and IXV
  * GIF strain meter (This signal was fed back to only ETMX)
  * [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=10376|klog#10376]]
  * [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=10301|klog#10301]]

 * simulation tools for Type-A control  are now being prepared.
  * /kagra/Dropbox/Personal/Fujii/TypeA/simulation/TypeAsimctrl_190902.slx
  * Still some of the paths are not connected
  * Soon the suspension ss-model is to be tuned especially about vertical resonances.

==== Plan for coming weeks ====
=== Type B ===
==== Report for the week 02-09-2019 ====
 * Shoda-san implemented new low frequency filters for the IMs using the oplev signals (e.g. klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=10355|10355]]).
 * With PEM team on Monday 2nd of September we put accelerometers on the two SR3 oplev platforms and on the large frame (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=10262|10262]]):
  * Above 10 Hz the coherence of the oplev readings with the upper platform accelerometer is high in several regions.
  * It  was possible to identify injected oplev noise into the suspension by  looking at the coherence between one of the accelerometers and the IM,  including large peaks between 16 and 18 Hz.
  * There's more information in the diaggui file which hasn't been analyzed.
 * On  Tuesday we moved SR2 and SRM oplev tilt QPDs to sensible positions  after the commissioning team re-aligned the interferometer (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=10291|10291]]).
  * I checked the OSEMs position and V2 is in an uncomfortable position: only 140 um from the end of linear range.
  * Although  until now I checked the position using the calibration information the  OSEM flag has been in a nearby position for since the end of May (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=9028|9028]]).
  * Due to a problem with the BF keystone, the clerance in the other direction is 140 um.
  * We decided to keep the keystone in the current position because it hasn't created any problems so far.
 * Nakano-kun  reported the BS was moving too much in yaw. I did some measurement and  noticed the inertial damping was injecting noise below 100 mHz (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=10354|10354]]).  At 50 mHz there's even a feature 2.4 times larger  with inertial  damping. We should just turn the inertial damping off. It also happens  that according to klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=9991|9991]], it is not working so effectively in reducing the integrated RMS.
 * Last  week I modified the real-time model to enable IP LVDT correction and  feedforward with seismometer signals on the ground. On Thursday I worked  inthe MEDM screen modification.
 * Terrence  updated Guardian after a report from Shoda-san concerning SR2: Guardian  was not tripping when the GAS filter coil driver hardware watchdog  tripped (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=10352|10352]]).  However, after the modification we realized of an additionl problem: in  a situation in which the TM coil driver should trip, the GAS filter  coil driver trips instead.

==== Plan for next week (09-09-2019) ====
 * Finish the MEDM screen  modification, install the real-time model and begin setting the LVDT  correction with the seismometer signal.
 * In order to minimize the injection of ground motion with the oplev, roll-off the oplev signal before it's used by any filter.
  * Use a cutoff frequency of about 8 or 9 Hz.
  * In  order to assess the amount of oplev control noise, ask Yokozawa-san to  leave the accelerometer at the oplev upper platform in order to measure  its coherece of the IM degrees of freedom.
 * Roll-off the GAS DC control filters in order to reduce the control noise in the observation frequency band.
 * Do we need to extend the GAS DC control filters to the micro-seismic region?

=== Type-Bp ===
==== Past week report ====
==== Plan for coming weeks ====
=== OMMT & OSTM (Takahashi) ===
==== Past week report ====
 * Evaluating the M2052 sample bar for OMC.

==== Plan for coming weeks ====
=== VIS electronics ===
==== Past week report ====
==== Plan for coming weeks ====
=== Other site works ===
=== Safety ===
 * Incidents:

== Discussion ==
 * Continued discussion on the VIS repair/upgrade work between O3 and O4
  * [[https://1drv.ms/x/s!Ajrs5Q_CgYCOkWbBTbTWvmOglafe|VIS task list for post-O3 work]]

== Travel Plans ==
 * Travel (Week of 9/9):
  * Takahashi:
  * Sato:
  * Hirata:
  * Shoda:
  * Fujii: At Kumamoto from 10th until 12th, for ASJ
  * Tanaka:

 * Travel (Week of 9/16):
  * Takahashi:
  * Sato:
  * Hirata:
  * Shoda:
  * Fujii: At Kamioka from ~14th until 30th
  * Tanaka:
  * Fabian: Away for the JPS meeting
  * Okutomi: Away for the JPS meeting

== Next meeting ==
On 2019/9/13(Fri)