Cryopayload's Action Item List

A/I#

Identified on

Assigned to

Status/Output

Related to

Description

Due date

001

2013 Nov. 19

Sekiguchi, Hirose

Closed. Takanori and Osamu Miyakawa found the document about OSEM (it includes the schematic design of circuit) by themselves.

Control

Ask somebody in LIGO details of the circuit for OSEM.

2013 Nov. 26

002

2013 Nov. 19

R. Takahashi

Closed. Unfortunately, there is not 3 dimensional but only 2 dimensional design drawing.->#016

Overall design

3-D design drawing of Type-A is necessary (ASAP!). Ask to Gianni.

2013 Nov. 26

003

2013 Nov. 19

R. Takahashi

Closed. Ryutaro explained. However, further discussion is necessary.->(#011)

Vertical spring

About blade metal spring (vertical spring), the schedule and strategy and so on will be summarized by R. Takahashi, Ishizaki, Sekiguchi, and K. Yamamoto, and reported in the next meeting.

2013 Nov. 26

004

2013 Nov. 19

K. Yamamoto

Closed. (1)Eric is busy. Moreover, Eric does not use ANSYS or COMSOL. However, Yoichi (or his student) will calculate it using COMSOL (Kazuhiro wrote Yoichi on Microsoft Project).(2)No files remain in Ando lab.

Material

About the masses, including a recoil mass, intermediate mass, intermediate recoil mass, and platform, the evaluation of the eddy current damping is necessary. K. Yamamoto will ask (1) to Eric Hennes how much he can make his effort for this problem and whether he can provide files for Finite Element Analysis. (2) to Ando or Aso whether Nishi's file for eddy current damping still remains.

2013 Nov. 26

005

2013 Nov. 19

D. Chen

Closed. The Picomotor didn’t work at 77K. But that might be because of the cooling shock. So we will have quick cooling test.

Control

D. Chen will ask Uchiyama whether a picomotor can survive at cryogenic temperature.

2013 Nov. 26

006

2013 Nov. 19

D. Chen

Closed. He received the design drawing from Takanori.

Control

D. Chen looks for design drawing of a stage for Type-B, and some commercial stages.

2013 Nov. 26

007

2013 Nov. 19

K. Yamamoto

Closed. Kazuhiro rewrote it.

Control

The schedule for the control system should be considered again.

2013 Nov. 26

008

2013 Nov. 19

K. Yamamoto

Closed. Dan asked Ryutaro.

Control

About the procurement of the OSEMs, K. Yamamoto will consult R. Takahashi.

2013 Nov. 26

009

2013 Nov. 19

T. Suzuki

Closed. Saito-san introduced ceramic bearing (and companies, NTN, NSKN). Takayuki Tomaru showed other one (http://www.jaxa.jp/press/nal/20020327_bearing_j.html) (#043). Now they will be order for test (#062)

Control

Check whether the thrust bearing can work at the cryogenic temperature. This part is necessary to adjust angle between intermediate mass and its recoil mass. But, it works for initial alignment. Thrust bearing is about 50mm in diameter and load is about 100kg.

2013 Nov. 26

010

2013 Nov. 19

D. Chen (?)

Closed. (i)In order to fix LED and PD, circuit board is used. We must check circuit board is OK at low temperature. -> #019(ii)Dan shows 7m cable increases the noise. Long cable can generates oscillation at high frequency region. The length of cables for cryo payload is 20m in length. We must check how much the long (flat) cable generates noise. If it is a problem, satellite boxes in vacuum are necessary. (iii)Window of photo detector will be removed because nitrogen gas is in Photo Diode.

Control

About OSEM, (i)check about out gas; (ii)check noises by 10-m long line; (iii)check whether the window of photodiode be removed.

2013 Nov. 26

011

2013 Nov. 26

T. Sekiguchi

Closed. Takanori summarized and explained.Vibration via heat link (T. Sekiguchi)->#017

Vertical spring

For the basis of discussion, Takanori will summarize the vibration via heat link until this weekend. After that, he and Ryutaro circulate their ideas about vertical spring and we discuss.

2013 Dec. 1

012

2013 Nov. 26

K. Yamamoto

Closed. (#105)

Vertical spring

Kazuhiro rewrites schedule.

2013 Dec. 3

013

2013 Nov. 26

K. Yamamoto

Closed. He explained. Strategies for sapphire monolithic suspension 2(K. Yamamoto)He also revised schedule.

Sapphire monolithic suspension

Kazuhiro will summarize the details of schedule for monolithic sapphire suspension based on above discussion by the next meeting.

2013 Dec. 3

014

2013 Nov. 26

T. Suzuki and K. Yamamoto

Closed. Now, members of SEO and EO recognized the issue, but how to fix ?

Sapphire monolithic suspension

Suzuki-san and Kazuhiro will report the serious lack of human resources on the next year to SEO and EO.

2013 Dec. 3

015

2013 Nov. 26

R. Kumar

Closed. Rahul investigated and explained Sapphire blade spring. Kazuhiro (Hayama) (and Kentaro and Yoichi) gave comments about data analysis (and noise and control).

Sapphire monolithic suspension

Rahul investigates how much the lowest frequency of sapphire spring is. After that, we ask it is a problem for observation to Data Analysis group.

2013 Dec. 10

016

2013 Dec. 3

R. Takahashi, E. Hirose

Closed. Takanori and Eiichi summarized Preliminary design of Type-A suspension system. Rahul’s new mission ->(#048).

Overall design

Type A 3 dimension drawing. Ryutaro gives Eiichi 2 dimensional design drawing and Eiichi makes drawings.

017

2013 Dec. 3

R. Takahashi, H. Ishizaki, T. Sekiguchi

Finally, this was ordered. The delivery date is 20th of January in the earliest case.

Vertical spring

Design drawing for vertical spring in platform (Ishizaki and Takahashi). Takanori takes care of shape of blade spring. The load on GAS in Type B like is different from that of Ad LIGO like.

018

2013 Dec. 3

K. Yamamoto

Closed. He summarized (in Japanese. Cryogenic payload strategy).

Material

Kazuhiro summarize requirement of magnetization and so on before the meeting with Sumikin

2013 Dec. 17

019

2013 Dec. 3

R. Takahashi

Urgent!

Control

Ryutaro will consult Saito-san on the outgas of circuit board for OSEM.

020

2013 Dec. 3

K. Yamamoto

Urgent! -> He explained. He will discuss with Sascha.

Sapphire monolithic suspension

Kazuhiro summarize the length of sapphire fiber. He must take bending point and adjustment of diameter into account

17 Dec 2013

021

2013 Dec. 3

K. Yamamoto

Closed. He summarized in Japanese (13 and 14 pages of payload strategy(in Japanese). Takanori calculated thermal noise of violin modes of heat link. Unfortunately, it is quite high Suspension Thermal Noise of Test Mass Suspension With Metal Wires + Heat Links in English.

Sapphire monolithic suspension

Kazuhiro write the report about backup plan.

17 Dec 2013

022

2013 Dec. 3

D. Chen

Closed. -> (#040)

Sapphire monolithic suspension

He considers structure in the intermediate mass (sapphire blades, stepping motor, stages). Later we discuss.

17 Dec 2013

023

2013 Dec. 10

T. Akutsu

Overall design

Baffle design : Mirror can observe the frame of hole of radiation shield for laser beam. It is an issue of scattered light. We also consider how to reduce the size of baffle. Other concerns are as follows; whether heat path on baffle is necessary ?, deformation under gravity, in the case of SolBlack … We must consider the structure between baffle and hole for laser beam on radiation shield.

024

2013 Dec. 10

Y. Aso, E. Hirose

Urgent! Kazuhiro summarizes points and consults with them.

Sapphire monolithic suspension

Yoichi Aso and Eiichi Hirose prepare the plan and R&D items of optical contact and screw, respectively.

24 Dec 2013

025

2013 Dec. 10

E. Hirose

Closed. Now this test is for “cradle” sapphire suspension with screws. Yusuke will summarize outline(#060).

Sapphire monolithic suspension

Eiichi prepares document describing planned test (100mm diameter sapphire bulk will suspended by sapphire fibers) and contributions.

24 Dec 2013

026

2013 Dec. 10

D. Chen

Closed. He asked and we discussed this topic.->(#041,042)

Sapphire monolithic suspension

Dan will ask Ryutaro what is pro and con of large intermediate mass.

17 Dec 2013

027

2013 Dec. 10

T. Suzuki

Closed. He released Sapphire surface friction.

Sapphire monolithic suspension

Suzuki-san has data of friction between sapphire and sapphire and he will circulate later.

17 Dec 2013

028

2013 Dec. 10

Y. Aso

Closed. Takanori did(#047).

Vertical spring

Yoichi checks vibration transfer function of heat links with extra pendulums and whether weight of mass of these pendulums can be on the order of kg using ANSYS or COMSOL.

029

2013 Dec. 10

T. Suzuki, S. Koike, C. Tokoku

Closed. Koike-san prepared Drawing payload and baffle in shield.

Overall design

Suzuki-san asks Koike-san to provide design drawing in shield. Tokoku-san learns how to handle it in CAD.

030

2013 Dec. 10

T. Suzuki, N. Kimura

In this time, we do not order. Kimura-san expects that small bunch can be ordered. Anyway, we obtained small test pieces.

Material

Suzuki-san (or Kimura-san) checks the schedule of procurement of NSSC130S.

17 Dec. 2013

031

2013 Dec. 10

Y. Sakakibara

Closed.Sphere was delivered. However, we must consider whether SolBlack is adopted or not.(->#071)

Material

Yusuke orders sphere made from SUS 316L and 305M to check how machining is difficult and whether deposition of SolBlack is OK.

032

2013 Dec. 10

C. Tokoku

Closed. She found that Cryogenic Research Center in Hongo campus has SQUID. She is preparing paper for submission. We can start the measurement at the beginning of the next year(->#071). Kazuhiro (Yamamoto) add this topic to Microsoft Project.

Material

Tokoku-san investigates where we can measure magnetism and asks measurement or measures.

17 Dec. 2013

033

2013 Dec. 10

T. Suzuki

Closed. He collected information (KOBELCO and Nippon Steel and Sumitomo Metal). Diameter is between 1 mm and 250 mm. Typical length is 4000mm.

Material

Suzuki-san asks companies (for example, http://www.ofa-titanium.com/product/titan/ti64.html) what kinds of geometry of Ti-6Al-4V are possible.

034

2013 Dec. 10

C. Tokoku, T. Suzuki

Everything was delivered.

Material

Tokoku-san prepares the mockup to research how to install wire between room and cryogenic temperature by end of next week. First of all, she checks where it will be in 101. Duct could be made from plastic. Wire is titan or its alloy. Suzuki-san prepares the stainless wire.

20 Dec. 2013

035

2013 Dec. 10

K. Yamamoto

Closed. Kazuhiro consults with Ettore. He summarized. 22-24 pages of Payload strategy (in Japanese).At least, monitor for installation is necessary.->(#087)

Material

Monitor system to check whether the wire between room and cryogenic temperature touches the cryoduct.

036

2013 Dec. 10

T. Suzuki, S. Koike

Closed. About 1.7 mm near center of shield floor. This point must be taken into account when we design cryo duct above radiation shield. (#061)

Material

Suzuki-san checks result of Koike-san’s calculation to evaluate the deformation of radiation shield after evacuation for design of cryoduct on radiation shield top.

037

2013 Dec. 10

Y. Sakakibara

Closed.　He summarized. Calculation of thermal radiation from SAS hole

Material

Yusuke calculate how the radiation into shield depends on the diameter of cryoduct.

17 Dec. 2013

038

2013 Dec. 10

D. Chen, R. Takahashi, T. Sekiguchi, E. Majorana

Closed. He summarized result Cryogenic meeting status report on 2013/12/17 (Control). The mass moved by stepping motor is on the order of kg.

Control

Dan will consult Takanori, Ryutaro and Ettore (how to evaluate the requirement for stepping motor for Type B or Virgo ? )

17 Dec. 2013

039

2013 Dec. 10

T. Suzuki

Closed. He reported AdhesiveTest. He recommends Nitofix. ->(#044). Othrewise, Araldite rapid.

Control

Suzuki-san reports the strength of glue for coil-magnet actuator in the next meeting.

17 Dec. 2013

040

2013 Dec. 17

R. Kumar, D. Chen

Closed. Takanori and Eiichi proposed first preliminary design. Preliminary design of Type-A suspension system.-> Rahul’s new mission (#048).

Sapphire monolithic suspension

”First design” of intermediate mass: Rahul fixs the details of sapphire blade springs. He will give information to Dan. Dan considers how blade spring and stage of stepping motor will be installed in intermediate mass and he evaluates moment of inertia.

25 Dec. 2013

041

2013 Dec. 17

S. Koike

Closed. He considered. Unfortunately, it is complicate. So, we do not investigate.

Sapphire monolithic suspension

Koike-san considers whether “cross structure” of sapphire blade spring is possible or not. If necessary, he adjusts the shape of blade spring. But if we need drastic improvement, we forget this idea.

25 Dec. 2013

042

2013 Dec. 17

R. Kumar, A. Khalaidovski

Closed. Rahul’s new mission (#048).

Sapphire monolithic suspension

Rahul improves the design of blade spring. Sascha will order.

25 Dec. 2013

043

2013 Dec. 17

K. Yamamoto

Closed. Kazuhiro summarizes what happened in CLIO and his guess about what happens in KAGRA 16-17 pages of Payload strategy (in Japanese). Vertical drift is an issue (->#086).

Overall design

Kazuhiro will ask Takashi Uchiyama how much CLIO suspension rotates during cooling.Kazuhiro Yamamoto summarizes the requirement of dynamic range of mirror position and yaw rotation because the top of Type A must be adjusted for this purpose. He also asks Takashi what happened in CLIO.

25 Dec. 2013

044

2013 Dec. 24

T. Suzuki

Urgent! Suzuki-san will reserve the out gas measurement system at KEK. For baking, the spacer between magnet and mirror is necessary because baking mirror with glued magnet causes contamination.

Control

Suzuki-san asks Saito-san whether Nitofix is ultra high vacuum compatibleOut gas.

045

2013 Dec. 24

D. Chen

Closed. He provided.

Sapphire monolithic suspension

Dan will provide information about size of stepping motor, stage and weight.

7 Jan. 2014

046

2013 Dec. 24

K. Hayama

Vertical spring

Kazuhiro Hayama evaluates the amplitude of gravitational wave from pulsars between 10Hz and 20Hz. He will take into account the direction of KAGRA interferometer and pulsars.

7 Jan. 2014

047

2013 Dec. 24

D. Chen

Closed. Dan explained his results.Vibration via heat links

Vertical spring

Dan and Takanori evaluated vibration via heat links with extra pendulum between cryo payload and cryocooler. Dan provides his shield vibration measurement result in Toshiba. Takanori will try simulation for heat links. Kazuhiro Yamamoto will give parameters.

7 Jan. 2014

048

2014 Jan. 8

R. Kumar

Closed. He did. Now, the target frequency is 14 Hz. Design is finished. Eiichi asked Shinkosha quotation.

Sapphire monolithic suspension

Rahul investigates folding sapphire blade spring by 10th of Jan.

10 Jan. 2014

049

2014 Jan. 8

K. Yamamoto

Closed. He counted and summarized in Japanese(17-18 pages of Payload strategy).

Material

Kazuhiro summaries the cables along bar between room and low temperature (control and thermometer)

14 Jan. 2014

050

2014 Jan. 8

E. Hirose, T. Sekiguchi

Closed. Platform. It could be on intermediate mass, but it is too busy.

Control

Eiichi and Takanori check whether thrust bearing is in platform or intermediate mass.

14 Jan. 2014

051

2014 Jan. 14

E. Hirose

Quotation arrived.

Sapphire monolithic suspension

Eiichi asks quotation for lower part in his idea.

21 Jan. 2014

052

2014 Jan. 14

T. Sekiguchi

Closed. He summarized his results Actuator Response of Cryogenic Payload with Different Suspension Points of Sapphire Fibers.

Sapphire monolithic suspension

Simulation to investigate the effect of the difference between the height of bending point and center of mass.

053

2014 Jan. 14

R. Kumar

Sapphire monolithic suspension

Rahul investigates thermal distribution model.

054

2014 Jan. 14

Y. Sakakibara

Unfortunately, annealing does not change the conductivity of copper. We must check whether size effect limits the conductivity or not.

Material

Yusuke measures annealed thermal conductivity of aluminum and copper. Higher temperature annealing could increase conductivity.

055

2014 Jan. 14

T. Suzuki

He found bundle. It consists of 734 thin lines (0.15 mm in diameter). 5N, 25 m in length.

Material

Suzuki-san looks for aluminum for CLIO in KEK.

21 Jan 2014

056

2014 Jan. 14

T. Sekiguchi

Urgent !Takanori is discussing with Ettore and Alessandro.

Control

We must decide strategy and schedule for LVDT

057

2014 Jan. 14

D. Chen, K. Yamamoto

Urgent !

Control

Out gas from Photo diode, LED and motor should be checked.

058

2014 Jan. 28

R. Takahashi

Closed. Ryutaro asked and the answer is yes. So, we must go ahead.(#068)

Overall design

Ryutaro asks PROMEC that they can and will provide design drawing for cryogenic payload.

059

2014 Jan. 28

T. Tomaru

Closed. He asked Hasegawa Kikai Sekkei. They also know company for high precision assembly. We must take care of topic, budget and so on.

Overall design

Takayuki will contact some Japanese companies to ask that they can support to design cryogenic payload.

060

2014 Jan. 28

Y. Sakakibara

Closed. Minute is here Minutes of sapphire suspension test meeting.

Sapphire monolithic suspension

Yusuke prepares the document of plan for test of "cradle" sapphire suspension with screws

061

2014 Jan. 28

T. Tomaru

He did.->(#073)

Overall design

Takayuki asks CAD specialists to design of cryo duct above radiation shield.

062

2014 Jan. 28

T. Suzuki

It was delivered.(#075)

Control

Suzuki-san orders ceramic bearing for test.

063

2014 Jan. 28

T. Tomaru

He did.

Overall design

Takayuki prepares wiki in KEK for design drawings.

064

2014 Feb. 4

T. Suzuki

Closed. Suzuki-san circulated Koike-san's result([kagra-aos 00482] 24 May 2013). According to this result, 2 ton weight can be supported.

Overall design

Suzuki-san checks the largest weight for port on the upper side of vacuum chamber of cryostat. Whether they can support the frame for assembly, installation and protection of dropping mirror ? If the payload is put on the frame, it can still support (it does NOT imply that the frame can catch when the payload drops without any damage)?

065

2014 Feb. 4

T. Akutsu

Overall design

Tomotada investigates ECB on Al6*** for wide angle scattered light baffle (although he has already asked ATC and they replied that it is possible).

066

2014 Feb. 4

K. Yamamoto

Closed. According to Miyoki-san's reply (3rd Feb 2014), this ceiling has crane. The largest weight is 2 ton. According to slides shown by Takayuki, it is 3 tons (this is the latest version).

Overall design

Kazuhiro Yamamoto asks Miyoki-san the strength of ceiling of clean room from point of view of installation of bottom filter (lowest part at room temperature) of Type A.

067

2014 Feb. 4

K. Yamamoto

Closed. Obuchi-san summarized his result Temperature distribution estimation of a wide-angle baffle (3). Kazuhiro replied (16 Feb 2014). Although temperature is 32 K in the highest case. However, radiation does not matter. Design will be in progress (->#023).

Overall design

Kazuhiro Yamamoto gives feedback about thermal simulation of baffle (requirement of temperature, heat path on baffle, deformation under gravity, in the case of SolBlack …).

068

2014 Feb. 4

R. Takahashi, T. Suzuki

Closed. If we would like to order PROMEC, KEK will order. In this case, the budget and so on must be taken care of.

Overall design

Preparation for PROMEC

069

2014 Feb. 4

K. Yamamoto

Closed.22nd and 23rd page of Cryogenic payload strategy (Japanese).

Control

Kazuhiro Yamamoto summarizes the effect of local Earth magnetic field fluctuation on coil magnet actuator.

070

2014 Feb. 4

K. Yamamoto

Control

Kazuhiro investigates the diffraction loss by coil.

071

2014 Feb. 18

C. Tokoku

Closed. http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=2321

Material

Tokoku-san summarizes measurement of magnetism of stainless (316L, NSSC130S) and Solblack and DLC.

072

2014 Feb. 18

T. Tomaru

He did. Improvement is necessary.

Overall design

Takayuki prepares 3 dimensional CAD drawing in radiation shield.

2014 Feb. 25

073

2014 Feb. 25

T. Tomaru and R. Takahashi

Closed. He did and introduce his idea about cryo duct and we discussed in this meeting (4th of March 2014).

Overall design

Takayuki asked Ryutaro details around boundary between room and cryogenic temperature.

074

2014 Feb. 25

T. Suzuki

Overall design

Suzuki-san discusses protection strategy for mirror and shield in SEO meeting.

075

2014 Feb. 25

Control

Ceramic bearing test

076

2014 Feb. 25

E. Hirose

Eiichi asked quotation.

Sapphire monolithic suspension

Eiichi asks CSIRO can polish barrel surface and make sapphire block which has round surface (curvature of radius is exactly same as that of mirror barrel surface).

077

2014 Feb. 25

T. Suzuki

Closed. Eiichi has a quotation.

Sapphire monolithic suspension

Suzuki-san checks old quotation about diffusion bonding from Japan cell.

078

2014 Feb. 25

T. Tomaru

Closed. He did it and shows the results and we discussed in this meeting (4th of March 2014).

Overall design

Takayuki investigates plan 3 for radiation shield protection. In this plan, the system will be installed to support ceiling of radiation shield to avoid break of radiation shield when cryo payload and so on drop.

079

2014 Feb. 27

K. Yamamoto

Closed. (#099)

Overall design

Kazuhiro fixes the dimension of wire between Bottom filter and Platform (Ti-6Al-4V) and check it can be manufactured.

080

2014 Feb. 27

K. Yamamoto

Overall design

Kazuhiro checks whether 80 cables can be along the metal wire between Bottom filter and Platform. Mockup (#034) can be useful.

081

2014 Mar. 4

T. Tomaru

Closed. He did and showed in this meeting Cryo duct on the ceiling of radiation shield.

Overall design

Takayuki circulates the design drawing of the cryo duct on the ceiling of radiation shield.

082

2014 Mar. 4

T. Suzuki

Closed. Unfortunately, it is not appropriate for our purpose. We must prepare and consider installation and jigs. It could be practice. ->(#090)

Overall design

Suzuki-san asks Toshiba whether there are still the flange plate at the top of cryostat for cooling test or not.

083

2014 Mar. 4

Sapphire monolithic suspension

Details of strength test of sapphire blade spring are considered (also clamp).

084

2014 Mar. 4

T. Tomaru

Closed. He reported.->(#094)

Overall design

Takayuki checks the view ports of cryostat for SHORT RANGE optical lever.

085

2014 Mar. 4

K. Yamamoto

Closed. Quotation arrived.

Sapphire monolithic suspension

Kazuhiro will ask Japan Cell quotation for direct bonding (5mm*10mm*20mm, 60 blocks).

086

2014 Mar. 6

Overall design

Vertical drift by thermal shrink

087

2014 Mar. 8

Overall design

Monitor system for top of the cryo duct on the ceiling of radiation shield. (only for installation ?, where (from bottom filter side)?, monitor system for wire to suspend bottom filter (there are appropriate view ports.))Optical view port ?

088

2014 Mar. 11

T. Tomaru

Overall design

Takayuki prepares "necessary item" list in wiki. If somebody finds something necessary, s/he writes it.

089

2014 Mar. 11

T. Tomaru

He and Suzuki-san has kick off meeting with Mitaka-koki.

Overall design

Takayuki looks for company for mechanical manufacture.

090

2014 Mar. 11

T. Suzuki, T. Tomaru

Overall design

Suzuki-san and Takayuki prepare the flange at the top of cryostat to separate cryostat from room temperature part.

091

2014 Mar. 11

K. Yamamoto

Material

Kazuhiro Yamamoto summarizes the requirement of magnetism.

092

2014 Mar. 11

T. Tomaru

Material

Takayuki investigates how to anneal tungsten.

093

2014 Mar. 11

Y. Sakakibara

Material

Yusuke check where Al samples with clamps for thermal resistance measurement.

094

2014 Apr. 9

T. Tomaru

Overall design

Takayuki will check effective aperture (because the window surface is not perpendicular to ray) of optical view port (400 mm above sapphire mirror).

095

2014 Apr. 9

T. Tomaru

Overall design

Takayuki will check the size of door of radiation shield as the upper limit of size of items in shield.

096

2014 Apr. 9

K. Yamamoto

Sapphire monolithic suspension

Kazuhiro Yamamoto asks Rahul details of how to attach ears on mirror with Hydroxide Catalysis Bonding. Or he asks somebody who stay in Kashiwa from Glasgow before GWADW.

097

2014 Apr. 9

T. Tomaru and K. Yamamoto

Control

Kazuhiro Yamamoto and Takayuki check or look for driver of stepping motor.

098

2014 Apr. 9

K. Yamamoto

Vertical spring

Kazuhiro Yamamoto will check three blades can be installed in 1/4 cryostat.

099

2014 Apr. 9

K. Yamamoto

Material

Ti-6Al-4V is the candidate as bar between low and room temperature. Kazuhiro Yamamoto will fix specification and ask company.

100

2014 Apr. 9

K. Yamamoto

Closed. 5th page of Cryogenic payload strategy(Japanese).

Material

Kazuhiro will check the thermal noise of heat links.

101

2014 Apr. 9

K. Yamamoto

Closed. Ryutaro replied. For test, they will prepare 3 OSEM with normal PEEK. One of them can be used for cryogenic test.

Control

Kazuhiro Yamamoto asks Takahashi-san status of OSEM.

102

2014 Apr. 15

T. Sekiguchi

Overall design

Takanori summarizes the requirement of optical lever and so on.

103

2014 Apr. 30

T. Tomaru and K. Yamamoto

Sapphire monolithic suspension

They look for sapphire bulk for test of ear connection (100mm in diameter ) in KEK and ICRR, respectively.

104

2014 Apr. 30

D. Chen, A. Khalaidovski, K. Yamamoto

Sapphire monolithic suspension

They make research plan in FY2014 based on Grant-in-Aid for Specially Promoted Research. It includes report of outline of sapphire mirror suspension (final version), purchase plan for fibers and so on, test of connection between mirror and ears, blade spring test, how to assemble.

105

2014 Apr. 30

R. Takahashi, K. Yamamoto

Vertical spring

Schedule must be revised (small sample test for material properties investigation and prototype for 1/4 cryostat and thermal compensation system).

106

2014 Apr. 30

T. Tomaru

Vertical spring

Takayuki prepares experiment for small sample test for material properties investigation.

107

2014 Apr. 30

T. Uchiyama

Overall design

Takashi Uchiyama checks whether MESCO knows the details of the new path from storage warehouse to KAGRA site.

108

2014 Apr. 30

T. Suzuki and T. Tomaru

Vertical spring

They prepare to move a tank of liquid nitrogen to ICRR.

109

2014 Apr. 30

D. Chen, K. Yamamoto

Sapphire monolithic suspension

They check the definition and calculation of bending length. It could be shorter than we expect.

110

2014 Apr. 30

D. Chen, R. Kumar

Sapphire monolithic suspension

Rahul or Dan calculate the violin modes with blade spring.

111

2014 Apr. 30

K. Yamamoto

Material

Kazuhiro Yamamoto check the effect of weight of heat link. For example, their weight can stretch the vertical spring.

112

2014 Apr. 30

K. Yamamoto

Overall design

Kazuhiro summarize memo Cryogenic payload strategy(Japanese). He add figure to show requirements of each part in cryo payload.