Differences between revisions 4 and 357 (spanning 353 versions)

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 12/17

BS
- Miyakawa-san worked on the BS real-time model and the gain/offset settings for the F0 LVDTINF block were lost, so we reentered them and did a new safe.snap file.
SRM
- We unlocked the IP adjusted the level with the jacks to center it. As hoped, this also improved the alignment of the chain insecurity structure and fixed a touching issue.
- Hirata-san installed and cabled the new F0 yaw stepper. We had allowed plenty of reserve mass, so there was no problem getting back to nominal height of the keystone. [As of Thursday afternoon, it had not yet been tested - UPDATE?]
- We found that the Nikhef method Fabian had used to tune the F0 LVDT driver gave an artificially narrow working range, so he retuned it with Enzo's method and recalibrated the LVDT.
- Fabian did a vertical position survey with all the GAS filters at nominal and found the height of the RM above the SS bottom plate was about 2.5 mm lower than in the CAD. This is about what we expected from a chain 7 mm longer than CAD and and F0 keystone set to 5 mm higher than CAD. In future we can survey to either the optic or the security structure as convenient, and we are in the range where we should easily be able to match the correct beam height with the jacks under the PI.
- We got two OL viewports for SRM from Akutsu-san, and will install them sometime in January, whenever we have a free moment. Akutsu-san pre-torqued the inner ring of screws around the glass, so we only need to torque the outer bolts.
SR3
- We also got a camera viewport for SR3 from Akutsu-san and will install it sometime in January.
- Hirata-san installed and cabled the new F0 yaw stepper.
SR2
- Enzo calibrated the SR2 OL. He noted that with the standard f=2500 mm collimator, the angular range was only about 100 µrad in pitch and 150 µrad in yaw, which is rather less than Enomoto-kun's preferred range of more like 400 µrad, so we borrowed f=1100 mm and f=3500 mm collimators to characterize. Enzo did f=1100 mm and will do f=3500 mm soon.
- Hirata-san installed and cabled the new F0 yaw stepper. We did not have enough reserve mass for SR2, so to save 300 g we had Mesco make a new, lighter top plate, and Hirata-san ultrasonically cleaned it. We were then able to get the desired F0 keystone height with about 200 g to spare.
Etc
- Enzo did a historical survey of the temperature as the various suspensions were being built and concluded that ideal operating temperature would be 25°C in the BS/SR2 area and 24°C for SR3/SRM.
- Mark wrote a bash script to log all the GAS filter heights and LVDT actuation offsets, and an Excel spreadsheet to analyze the data to get an overview of the heights of the suspensions and the amount of height adjustment being used. He also reviewed old TF data to get near-DC values for the effect of GAS actuation on GAS height. This uncovered a few issues with calibration settings (such as for BS F0) having been lost because they hadn't been recorded in a safe.snap file, which we fixed.

To-Do Lists, Schedule

Plan for week of 12/17

Final alignment of SRM payload, plus BF and SF GAS.
(Time permitting) unlocking/centering/tuning of IP.
Installation of Enomoto-kun's beam target on SRM (if available).
Installation/testing of F0 steppers on SR2, SR3, SRM, and (hopefully) final vertical height adjustment.
Installation of viewports on SRM.

Plan for weeks of 12/24, 12/31

Most of team on holidays - no Kamioka work.

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).

Vacation/Etc Info

Mark: 12/24 - 1/4.
Hirata-san: 12/24 - 1/4.
Fabian: 12/31 - 1/4
Enzo: 12/31 - 1/4.
Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.
Terrence: back at Kamioka from 1/7.

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

-  ⇤ ← Revision 4 as of 2016-04-15 12:02:42 → 
  Size: 14643
  Editor: MarkBarton
  Comment:
+   ← Revision 357 as of 2018-12-21 11:14:07 → ⇥
  Size: 4710
  Editor: MarkBarton
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 5:
- * Electronics
  * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3600| D1503600-v9 BS Suspension Cabling]]
  * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5111| E1605111-v1 BS Suspension Electronic Items List]]
  * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3901| D1503901-v2 In-Vacuum Cable Detail]]
  * Need to hand-make geophone cables
  * Need to make longer versions of BF-PI and SF-PI cables (3.7 m and 2.5 m)
  * Need to check OSEM cables have same flip for flexicircuit as for PRx.
  * Asked Miyakawa-san for status on AEL items, especially stepper driver.
 * Compensation masses for RM/IRM ordered, expected 4/29
+=== Type B (Mark) ===
==== Report for week of 12/17 ====
 * BS
  * Miyakawa-san worked on the BS real-time model and the gain/offset settings for the F0 LVDTINF block were lost, so we reentered them and did a new safe.snap file.
 * SRM
  * We unlocked the IP adjusted the level with the jacks to center it. As hoped, this also improved the alignment of the chain insecurity structure and fixed a touching issue.
  * Hirata-san installed and cabled the new F0 yaw stepper. We had allowed plenty of reserve mass, so there was no problem getting back to nominal height of the keystone. [''As of Thursday afternoon, it had not yet been tested - UPDATE?'']
  * We found that the Nikhef method Fabian had used to tune the F0 LVDT driver gave an artificially narrow working range, so he retuned it with Enzo's method and recalibrated the LVDT.
  * Fabian did a vertical position survey with all the GAS filters at nominal and found the height of the RM above the SS bottom plate was about 2.5 mm lower than in the CAD. This is about what we expected from a chain 7 mm longer than CAD and and F0 keystone set to 5 mm higher than CAD. In future we can survey to either the optic or the security structure as convenient, and we are in the range where we should easily be able to match the correct beam height with the jacks under the PI.
  * We got two OL viewports for SRM from Akutsu-san, and will install them sometime in January, whenever we have a free moment. Akutsu-san pre-torqued the inner ring of screws around the glass, so we only need to torque the outer bolts.
 * SR3
  * We also got a camera viewport for SR3 from Akutsu-san and will install it sometime in January.
  * Hirata-san installed and cabled the new F0 yaw stepper.
 * SR2
  * Enzo calibrated the SR2 OL. He noted that with the standard f=2500 mm collimator, the angular range was only about 100 µrad in pitch and 150 µrad in yaw, which is rather less than Enomoto-kun's preferred range of more like 400 µrad, so we borrowed f=1100 mm and f=3500 mm collimators to characterize. Enzo did f=1100 mm and will do f=3500 mm soon.
  * Hirata-san installed and cabled the new F0 yaw stepper. We did not have enough reserve mass for SR2, so to save 300 g we had Mesco make a new, lighter top plate, and Hirata-san ultrasonically cleaned it. We were then able to get the desired F0 keystone height with about 200 g to spare.
 * Etc
  * Enzo did a historical survey of the temperature as the various suspensions were being built and concluded that ideal operating temperature would be 25°C in the BS/SR2 area and 24°C for SR3/SRM.
  * Mark wrote a bash script to log all the GAS filter heights and LVDT actuation offsets, and an Excel spreadsheet to analyze the data to get an overview of the heights of the suspensions and the amount of height adjustment being used. He also reviewed old TF data to get near-DC values for the effect of GAS actuation on GAS height. This uncovered a few issues with calibration settings (such as for BS F0) having been lost because they hadn't been recorded in a safe.snap file, which we fixed.
-Line 15:
+Line 25:
- * Hirata-san drew up flags
 
   * Lots of new drawings - see above or [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5035| E1605035 VIS Document and Drawing Tree (BS)]]
+==== 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)]]
-Line 19:
+Line 30:
-= VIS Meeting on 2016/4/15 =
2016/4/15 13:30 -
+==== Plan for week of 12/17 ====
 * Final alignment of SRM payload, plus BF and SF GAS.
 * (Time permitting) unlocking/centering/tuning of IP.
 * Installation of Enomoto-kun's beam target on SRM (if available).
 * Installation/testing of F0 steppers on SR2, SR3, SRM, and (hopefully) final vertical height adjustment.
 * Installation of viewports on SRM.
-Line 22:
+Line 37:
-Room 210 & eZuce
+==== Plan for weeks of 12/24, 12/31 ====
 * Most of team on holidays - no Kamioka work.
-Line 24:
+Line 40:
-Participants:
+==== 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).
-Line 26:
+Line 50:
-== Schedule ==
 * #Schedule status (Aso)
 * #Will have a schedule meeting with Ando-san on April 15th in Kamioka (Takahashi, Mark, Shoda will come)

== iKAGRA related activities ==
== PR3 ==
 * PR3 Operation Status (Aso)
  *
 * Traverser and Stepper motor remote control (Shoda):
  * Aso will send a stepper motor driver from Kamioka to Mitaka for test.-> Done

== iKAGRA ETM suspension ==
 * Current status (Ohishi)

== Electronics ==
 * What are necessary in the next few weeks ?
  * BS:
   * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3600|JGW-D1503600 - BS Suspension Cabling]]
   * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5111| E1605111 BS Suspension Electronic Items List]] 
   * Gave dates to Miyakawa-san and asked for feedback and status (no reply yet). Also, some issues with previously ordered cables were brought to attention of Takahashi-san.

 * Watch dog system (Tanaka)
  * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5108|Graceful shutdown mechanism]]

  * Will give a presentation at the next AEL meeting on 4/18

 * #Electronics diagram and review
  * #Electronics document tree for VIS by Mark ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4937|E1604937]])
  * #Updated PR3 schematic with OpLev wiring ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4795|D1604795]])
  * #Who will manage the electronics of each suspension
   * Type-Bp will be controlled by Shoda but the diagram update will be done by Mark
   * Type-A may be maintained by a new engineer. Sould be discussed with the person before April .
  * #We need to count electronics and cables needed for the tests, such as temporary sensors and so on.

== bKAGRA preparation ==
 * Three big categories of the tasks
  * Type-A: Leader = Takahashi, Okutomi, Ishizaki, a new engineer
  * Type-B (BS and SRC): Leader = Mark, Fabian, Hirata
  * Type-Bp modification: Leader = Shoda, Fujii, A new technician (?)

== Common Issues ==
 * Policy of the screw types to be used (Mark, Fabian) [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5107|E1605107]] ([[https://onedrive.live.com/redir?resid=1447B05D5B571A84!346&authkey=!ABNrIarsklTd8Q0&ithint=file,docx|draft]])
 * Reflection type local sensor (Akutsu)
  * Test widening the opening next week (Akutsu) -> [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=1459|report]]
  * Continue to work on how to fit the reflective sensor into the current coil bobbin (Akutsu)
 * OSEM assembly (Akutsu)
  * Schedule for each suspension is now given to Akutsu-kun

== Type-B ==
 * [[KAGRA/Subgroups/VIS/TypeB]]
 * [[https://onedrive.live.com/redir?resid=D5CCFA70A378E0D0!185&authkey=!AGcFDradxzrNJ00&ithint=folder,txt|Task list/schedule]]
 * Past Week Summary
  * Mark posted [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3600|JGW-D1503600 - BS Suspension Cabling]], did a summary [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5111| E1605111 BS Suspension Electronic Items List]] and asked Miyakawa-san for feedback and status (no reply yet). Also, some issues with previously ordered cables were brought to attention of Takahashi-san.
  * Mirapro sent assembly frame quote based on [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5037|E1605037]]
  * Mark designed a clean bag [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5123 | T1605123]]
  * Fabian continued analysis of wire thickness versus mode frequency: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5106|T1605106]] ([[https://onedrive.live.com/view.aspx?resid=1447B05D5B571A84!354&ithint=file,docx&app=Word&authkey=!AO5CHNP3xlO5RjY|draft]])
  * Hirata-san investigated and found a good height for secondary prism was 3 mm. He drew up the dummy primary prisms and the secondary prisms: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5125| D1605125]]
  * Hirata-san did drawings for the flags: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5087| D1605087 Flag for BS RM]], [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5088| D1605088 Flag for BS IM]]
  * Hirata-san asked for quote on prisms and flags.
  * Hirata-san did assembly drawings for the safety bar between IM and RM and for the EQ stop: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5127| D1605127]], [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5124|D1605124]], [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5112| D1605112 Flag for BS IM type2]]
 * Can we make SR wire breakers bigger?
  * Fukushima-san preparing test: 3/4/2016 + 1 month = ≈4/1/2016 -> Hirata-san and Takahashi-san talking to ATC 4/8 morning.
 * Flag design
  * [[https://onedrive.live.com/redir?resid=D5CCFA70A378E0D0!279&authkey=!ABLGQZIFvuQFtz4&ithint=folder,dwg|BS Flag Redesign on OneDrive]]
   * Drawings done, RFQ issued:  [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5087|D1605087]], [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5088|D1605088]], [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5112| D1605112]]
  * Widen the OSEM opening (Akutsu)
  * A new local length sensing
   * Need to decide the strategy for BS: three choices
    * Use OSEMs as originally planned
    * Use OpLev, No OSEM flag
    * Use reflection type sensors, No OSEM flag
   * Decide later!
 * BS dummy optic
  * Ordered, expected ≈4/22 ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4811|T1604811]])
 * Prisms
  * New drawings for dummy primary prisms and secondary prisms: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5125| D1605125]], safety bar between IM and RM [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5127| D1605127]], and for the EQ stop [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5124|D1605124]]
 * EQ stop screws, extensions and lock nuts (in manufacture - promised for 4/22)
 * Ballast masses for payload
  * Hirata-san created drawings [[https://www.dropbox.com/sh/t5tfj9uvdkldk1d/AAB0ypH6SZpZjBYK0E0416Lwa?dl=0|DropBox link]]
  * Drawings were checked by Mark, not yet ordered.
 * Lower breadboard stuff
  * Breadboard spring bases and associated cable clamps (in manufacture, expected 4/15)
  * Breadboard springs (in manufacture)
  * Damper ring mods (in manufacture, expected 4/28)
  * Nail-head parts: quote from Mirapro received, not urgent, will be combined with assembly frame order.
 * BS Assembly Frame Design (Mark, Hirata)
  * Quote received, drawings being checked. Will need minor modifications to support clean bag (see below).
 * Clean bag
  * Design done: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5123 | T1605123]]
  * Aso-san will order
 * 2D and 3D CAD
  * BS 3D Assembly
   * Lots of new drawings - see above or [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5035| E1605035 VIS Document and Drawing Tree (BS)]]
   * 3D CAD for BS assembly frame received from Mirapro - Hirata-san is adding clean bag extension and rail stuff.
 * Electronics
  * Lots of work:
   * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3600|JGW-D1503600 - BS Suspension Cabling]]
   * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5111| E1605111 BS Suspension Electronic Items List]] 
   * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3901| D1503901 In-Vacuum Cable Detail]]
   * Item list and timetable was given to Miyakawa-san.
   * Need to get new longer versions of some previously ordered BF-PI and SF-PI cables (Takahashi).
   * Need to check previously ordered TM-BF and IM-BF OSEM cables have been flipped (Takahashi).
   * Decided to hand-make cables for geophones because previously ordered cables have no conductor on pin 5.
   * Need to get status on design of stepper drive box (requested by Sekiguchi-san [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3385|T1503385]])
 * Procedure documents
  * No action since last week
 * Mirror box (Tatsumi)
  * Hirata-san is working on this as top priority - design decided, drawings being checked, will get them to Tatsumi-san ASAP.
  * BS clamp blocks already adjusted.
 * Not enough crane height problem (Hirata, Saito)
  * No action since last week

== Type A ==
 * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4792|Task list]] (Takahashi)

 * Prototype test<<BR>>
  * The prototype EQ stop was transported from Kashiwa to Kamioka on 31th March.
  * Assembly of the EQ stop prototype on 6-7 April next to the SR3 chamber. -> Found a lot of things to improve. Report by Okutomi.
   * Will redeisgn the EQ stops for the actual Type-A suepsnions.
  * Demonstration of installation procedure using prototype filters (SFx1 + BFx2) from May
   * Use the prototype EQ stops with the old Type-B assembly frame
   * Clean booth construction for SR will start from July 1st.
   * The location will be between SR2 and SR3. Will talk with Saito-san if this plan is OK or not on 4/15 (Takahashi)
 * The next Type-A meeting will be on 4/14.
 * The test of prototype long maraging rod was started. Detail is here: http://klog.icrr.u-tokyo.ac.jp/osl/index.php?r=1185
  * Load dependence was measured using a laser position sensor. Extension of 2.84mm was observed for the load of 272.8kg. The extension is consistent with the calculation (2.75mm).
 * Maraging rod preparation status
  * 2 sets for magnetic dampers are missing
  * 4 long maraging rods will
 * Care on the humidity should be taken to store maraging steel to avoid cracking noise.

 * Type-A Filters Optimal Load Measurements
  * Started the measurements and installation of fishing rods: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5105|report]]
 * Simultion (Okutomi)
  * Simulation with a dummy payload (report)
  * Will update the seismic noise data.
  * Need to implement the damping control part to see the damped RMS.
  * Ballast masses for the top filter may interfere with the magic wands.
   * Need to check how many ballast masses are necessaryfor Type-B and see if they interfere (Mark). If so we need to modify the mass like making some cuts.

== Type-Bp modification ==
 * This Week
  * Working on the CAD model and control simulation of BF modification (Shoda)

  * Details will be reported at the next meeting.
 * Traverser motor driver (Shoda)
  * Need a box for stepping motor driver. Miyakawa-san is thinking about ordering chassis and boxes for motors. We discussed and agreed that the design of the boxes will be unified. The boxes will be designed and ordered together with those. (16/03/10)
  * Miyakawa-san wants to have a driver and a motor to test
   * Will give them to MIyakawa-san when Shoda-san come to Kamioka for the shifts
    . -> Done (3/28)
    * Shoda is also asking Uraguchi-san to provide one more Traverser motor driver for the test.

 * Modification for bKAGRA
  * [[KAGRA/Subgroups/VIS/TypeBp|wiki]]
   * Uraguchi-san proposed us the new IP plan
   * Shoda updated the proposal(concerns?) for the BF active damping plan

  * Action items for Type-Bp modification
   * Calculate the upper limit of the resonant fequency for IP (Fujii): [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5096|MeetingMemo]]
   * Check if we need the magnetic damper for the bottom filter (Fujii): [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5096|MeetingMemo]]
    * Either the MD is used or the resonant frequency of the IP should be matched with the whole chain resonance.
   * Check the mass of the bottom plate and the cap of the standard filter -> Send Uraguchi-san (Shoda)
    . -> Done (3/31)
   * Check structure analysis of the EQ stop for active damping on BF (Shoda)
   * Check the minimam weight we need for the BFRM in order to damp the resonance enough (Shoda)
   * Check the capability to modify the BF cap (Shoda)
    . '''We want the correct CAD model for the original Type-Bp'''
    * The BF and SF designs are the same for Bp and B except for the blades. So the effort to make correct CAD models for those filters can be unified between the two teams. Hirata-san with help from Shoda-san will work to make correct CAD models.

  * Will have a meeting with Virgo people sometime soon. Then have a review for Type-Bp

== Site work plan for the next week ==
 * Mon:
 * Tue:
 * Wed:
 * Thu:
 * Fri:

== Travel Plans ==
 * Travel (Week of 4/18)
  * Takahashi:23-25 (Shift)
  * Shoda:
  * Mark:
  * Fabian:
  * Okutomi:
  * Fujii:
  * Ishizaki:
  * Hirata:
  * Ohishi:

 * Travel (Week of 4/25)
  * Takahashi:
  * Shoda:
  * Mark:
  * Fabian:
  * Okutomi:
  * Fujii:
  * Ishizaki:
  * Hirata:
  * Ohishi:

== Other ==
 * Safety
  *

 * #GAS blade inspection by Virgo (Takahashi)
  * Shipped the blades. Will get results in 1-2 months.

== Next meeting ==
2016/4/22 (Fri) 13:30 -
+==== Vacation/Etc Info ====
 * Mark: 12/24 - 1/4.
 * Hirata-san: 12/24 - 1/4.
 * Fabian: 12/31 - 1/4
 * Enzo: 12/31 - 1/4.
 * Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.
 * Terrence: back at Kamioka from 1/7.