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

S. Zeidler

Tomotada emphasized that the first priority is to fix the problem of magnetism of black coating. Asahi precision is investigating how to reduce the magnetism of SolBlack. The requirement of magnetism must be clear soon. The design of the recoil mass should be released soon (almost it has already been written). The space for baffle in shield must be taken care of. The suspension for baffle will be design.

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.　-> Simon starts the investigation.

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 not only Nitofix but also Master bond. 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

Closed. He summarized his results (http://wiki.kek.jp/display/gw/Payload+Cool+Down).

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

Closed. Electro-chemical buffing (ECB) on A6xxx is possible and it is approved by Tomotada. On the 17th of June 2014, Azuma-san from Nichizo-Seimitsu Kemma corp. brought Tomotada a sample of ECBed A6xxx, and he did a visual inspection on it, and he felt it is sufficient.(->#135)

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

Closed. ->(#156)

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

T. Suzuki, T. Tomaru

Control

Ceramic bearing test

076

2014 Feb. 25

E. Hirose

Closed. Unfortunately, quotation itself is challenging.

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

Closed. p26-31 of Cryogenic payload strategy(Japanese).

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). Ettore suggested the measurement of resonant frequency of horizontal motion of sapphire blade spring.

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

Takayuki put screw holes on the top plate.

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

Closed. Takayuki prepared (便利な道具・必要物品（Tool list） on KEK wiki).

Overall design

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

089

2014 Mar. 11

T. Tomaru

Closed. He and Suzuki-san has kick off meeting with Mitaka-koki. They visited Mitaka-koki and Oshimashisaku on the 6th of June 2014.-> Kume-san introduces a company (VIC international). They come KEK on the 2nd or 3rd of July for the meeting. -> Kume-san is a contact person for VIC international.-> Suzuki-san and Takayuki will visit VIC on the 12th of November.->We ordered test fabrication of intermediate mass part to VIC.

Overall design

Takayuki looks for company for mechanical manufacture.

090

2014 Mar. 11

T. Suzuki, T. Tomaru

Hagiwara-san wrote design.

Overall design

Suzuki-san and Takayuki prepare the flange at the top of cryostat to separate cryostat from room temperature part.　This flange must have ears for installation.

091

2014 Mar. 11

K. Yamamoto

Closed. He did. p8-9 of Cryogenic payload strategy(Japanese).->(#118)(#164)

Material

Kazuhiro Yamamoto summarizes the requirement of magnetism.

092

2014 Mar. 11

T. Tomaru

Closed. He did.->(#117)

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

Closed. He showed the result in the integration meeting (13 May 2014)->(#102)

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

Marielle van Veggel and Kazuhiro Yamamoto discussed and Kazuhiro summarized (Marielle (2014 May 23).docx on KEK wiki).

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

Closed. Takayuki got control circuit kit to operate pytron stepping motor.

Control

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

098

2014 Apr. 9

K. Yamamoto

Closed. (#105)

Vertical spring

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

099

2014 Apr. 9

T. Kume and K. Yamamoto

Kazuhiro will summarize the specification of Ti-6Al-4V bar (shorter one when the cryostat is separated from room temperature part). Hagiwara-san will draw design and Kume-san asks the company. The number is 2 or 3.-> We must consider the details of cryo payload at the same time. It is useful to make test piece with nail head.

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

CRY

Overall design

CRY summarizes the requirement of optical lever and so on (motivation and design, wavelength, budget …). CRY is charge of optical lever near cryostat

103

2014 Apr. 30

T. Tomaru and K. Yamamoto

ICRR has two pieces. We can use them.

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, T. Tomaru

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

Closed. The answer is yes.

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

Closed. It is not necessary because 1/4 cryostat will be moved to KEK.

Vertical spring

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

109

2014 Apr. 30

D. Chen, R. Kumar, K. Yamamoto

In progress. Bending length of thick fibers and Cryogenic meeting on 2014/8/26(chen)-> Still in progress Bending length evaluation.-> Kazuhiro proceeded with analytical investigationAnalytical investigation about bending length. He found that “geometrical” bending length is different from “physical” one. The latter is almost the same as “traditional” one. Dan will try simulation for “physical” bending length. If he shows new result within one week, we revise the design for Zygo (#157).-> Unfortunately no results. Thus, we adopt Kazuhiro’s analytical formula.(#159)

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

Closed. According to Rahul’s slides Thermal noise performance of the cryogenic sapphire suspension system for the KAGRA detector, the 1st violin mode frequency is 221 Hz. Dan also showed similar result Cryogenic meeting on 2014/8/5(chen). According to Kazuhiro’s analytical calculation Thermal noise in KAGRA (GWADW2014), 1st violin mode frequency WITHOUT blade spring is 220Hz. So, blade spring does not change violin mode drastically.

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

Closed. Cryogenic payload requirement(English).

Overall design

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

113

2014 May 13

T. Tomaru

Direction of shutter must be checked.

Overall design

Takayuki checks how to remove the optical window of the radiation shield.

114

2014 May 13

T. Suzuki, N. Kimura, T. Tomaru

Closed. We decide that SI of Toshiba duct is used as vacuum duct. SI of this duct is reused for pipe of SAS.

Overall design

Suzuki-san, Kimura-san, and Takayuki discuss whether SI of Toshiba can be used for cryo duct on the radiation shield.

115

2014 May 13

S. Koike

Closed. Strength is enough large.

Overall design

Koike-san check the strength of ceiling of radiation shield (whether somebody can assemble this duct or not).

116

2014 May 13

Overall design

Design for jigs to fix and summarize cables along SAS and cryopayload chain.

117

2014 May 13

D. Chen

Material

Dan will measure Q and thermal conductivity tungsten annealed by Takayuki.

118

2014 May 13

Y. Sakakibara

Material

Yusuke evaluate effect of magnetism using ANSYS in order to check Kazuhiro’s calculation (#091).

119

2014 May 13

R. Kumar

Rahul started design.

Sapphire monolithic suspension

Rahul prepares the measurement of mechanical loss on the surface of sapphire fibers.

120

2014 May 13

Control

Measurement or evaluation of 300K radiation through a optical window

121

2014 May 13

T. Tomaru

Control

Takayuki asks Hagiwara-san to check CAD about tunnel for optical laver.

122

2014 May 13

K. Yamamoto

Closed. It was delivered.(->#137)

Control

Kazuhiro will order master bond

123

2014 May 13

K. Yamamoto

Closed. Ettore said that quadrupole is not discussed so far.

Control

Kazuhiro asks Ettore whether the quadrupole of a tine magnet is a problem in coil magnet actuator.

124

2014 May 13

K. Yamamoto

Closed. Luca's paper is here [http://iopscience.iop.org/0957-0233/25/1/015103/article]. Although resistance of coil at cryogenic temperature is much smaller, calibration coefficient is independent of temperature because circuit components are moved outside cryostat if possible. Displacement sensitivity is 50pm/rtHz.

Control

Kazuhiro checks Luca’ paper (a part of LVDT).

125

2014 May 13

D. Chen

Control

Dan consults Jena people (requirement of moving mass).

126

2014 May 20

T. Tomaru

Material

Takayuki prepares the annealed tungsten wires for Q and thermal conductivity measurement.

127

2014 May 20

D. Chen

Closed. Discussion is in progress. Now flatness is an issue. It is not so good (around lambda) for Hydroxide Catalysis Bonding. Dan will ask how much flatness of small block is. After reply, we discuss. ->Flatness is OK in the case of small block. We will order soon.-> Flatness is ok even if the block is large with small polished area. We ordered on the 27th of June 2014.

Sapphire monolithic suspension

Dan will ask whether Shinkosha have pieces whose size is similar to what he wants for one fiber prototype test.

128

2014 May 20

D. Chen

Closed. Takayuki proposed new cut (it is not parallel). Dan checks the peeling stress (Strength.pdf and strength(2).pdf). Sascha started the discussion with IMPEX.

Sapphire monolithic suspension

Dan will evaluate stress of peeling between ears and mirror. Moreover he designs flat cut and ears.

129

2014 Jun. 3

Closed. Kazuhiro asked Saito-san. Duct for Type A chains will be delivered on the 11th of Aug. And they will be installed in shaft soon. The part which is between cryostat and Type A chain (it includes 900mm diameter ports for GAS filter connected to cryopayload) will be put near cryostat. It will be installed later and jigs for installation is necessary. Design (structure) and schedule of clean booth must be clear (#142).

Overall design

Installation procedure of duct for Type A chain and cryostat must be checked.

130

2014 Jun. 3

K. Yamamoto

Closed. We reuse sapphire cylinder for indium bonding.

Sapphire monolithic suspension

Kazuhiro will ask status of sample for Q measurement of Hydroxide Catalysis Bonding.

131

2014 Jun. 3

D. Chen, K. Yamamoto

Closed. Jena group kindly provided.

Sapphire monolithic suspension

Dan checks where indium is. If necessary, Kazuhiro purchases and send it to Jena.

132

2014 Jun. 10

D. Chen

Closed. He result shows that it does not matter. test.pdf on Simulation of sapphire suspension under gravity

Sapphire monolithic suspension

Dan checks effect by stress of slit of the blade spring.

133

2014 Jun. 17

T. Suzuki, N. Kimura, T. Tomaru

Closed. We can use the car from the beginning of August.

Overall design

Car leasing must be prepared.

134

2014 Jun. 17

T. Akutsu

Overall design

Tomotada must fix which new cryoduct or Toshiba one will be used for BS side.

135

2014 Jun. 24

T. Akutsu and somebody

Overall design

Measurement of scattering distribution and specular reflectivity of SolBlack on Electro-chemical buffing (ECB) on A6xxx

136

2014 Jun. 24

S. Koike

Closed. He did it.

Overall design

Koike-san will prepare drawing of parts (for cost evaluation) of pipe for SAS.

137

2014 Jun. 24

K. Yamamoto

Closed. Suzuki-san brought master bond and stainless steel for out gas test.->(#044).

Control

Suzuki-san brought stainless steel for out gas test of Master Bond. Kazuhiro will prepare (0.1mm in thickness).

138

2014 Jun. 24

T. Suzuki

Control

Mitsubishi cable industries can provide polyimide line for coil. Suzuki-san checks out gas .

139

2014 Jun. 24

K. Yamamoto

Vertical spring

Kazuhiro will summarize the requirement and so on.

140

2014 Jul. 08

T. Suzuki

Overall design

Suzuki-san consider shift at KAGRA site (before assembly).

141

2014 Jul. 08

Y. Sakakibara and somebody

Closed. Kume-san succeeds.

Overall design

Somebody will learn how to use application software and calculate transfer heat and so on (Yusuke will teach).

142

2014 Jul. 15

T. Suzuki and N. Kimura

Overall design

Suzuki-san and Kimura-san discuss the assembly schedule and structure of clean booths.

143

2014 Jul. 23

K. Yamamoto

Closed. He revised old report. measurement of mechanical loss of attachment of actuator and fiber

Control

Kazuhiro checks his old calculation to evaluate thermal noise by magnet before Dan will calculate.

144

2014 Aug. 26

Overall design

We must check whether there is the contradiction between setting base-pin and wall painting.

145

2014 Aug. 26

Overall design

We decide concrete requirement for measurement and alignment accuracy.

146

2014 Aug. 26

K. Yamamoto

Closed. Dan summarized. Requirement of mechanical loss in http://wiki.kek.jp/display/gw/Sapphire+suspension.

Sapphire monolithic suspension

Kazuhiro will summarize the requirement of loss in each part of sapphire suspension in schematic view.

147

2014 Aug. 26

K. Yamamoto

Kazuhiro Hayama explained impact of first violin modeバイオリンモードスタディ. The length should be between 300 mm and 350mm.

Sapphire monolithic suspension

The sapphire fiber length must be decided soon.

148

2014 Aug. 26

T. Tomaru, S. Koike

Overall design

Takayuki and Koike-san simulate the internal mode of the platform.

149

2014 Aug. 26

R. Kumar

Sapphire monolithic suspension

Rahul summarizes his result file and their explanation for somebody else and writes short report for the paper.

150

2014 Aug. 26

K. Yamamoto

Closed. Gravitational Wave Project Office decided to keep the licenses in the next one year. ANSYS server will be in ICRR. People in KEK can access via VPN. If Rahul needs this server as an excellent computer, he will conduct the procedure (he changes server machine and so on… ).

Sapphire monolithic suspension

Kazuhiro consults Miyoki-san to keep ANSYS licenses in Gravitational Wave Project Office, ICRR and to move Rahul's server to KEK.

151

2014 Aug. 26

K. Yamamoto

Closed. Karen reported the result on 10th of Feb, ELiTES meeting (http://events.ego-gw.it/indico/getFile.py/access?contribId=14&sessionId=3&resId=0&materialId=slides&confId=16).

Sapphire monolithic suspension

Kazuhiro asks Sheila Rowan the status of Hydroxide Catalysis Bonding.

152

2014 Sep. 9

T. Tomaru

Closed. He did it. http://wiki.kek.jp/display/gw/Photo

Overall design

Takayuki prepares summary page for photos on KEK wiki.

153

2014 Sep. 9

T. Akutsu

We discussed (17 Sep 2014) and CRY group have no preference of the direction of the wedge direction (if the the ray is on the horizontal plane).-> We discuss again (21 Oct 2014). Kimura-san circulated e-mail that day. We must decide the direction of this duct by 24th of Oct. We discussed and agreed as follow; the duct is on the narrow side. However, we must check some details.(#165)(#166)(#167).

Overall design

Since the ETM has wedge (0.2degree +/-0.1 degree), the angle between duct shield behind ETM and optical axis cannot be zero. Tomotada will summarize details (angle, which side, and so on …) and tell Kimura-san later.

154

2014 Sep. 9

K. Yamamoto, T. Suzuki

Closed. We had the meeting on the 3rd of Oct. We will purchase as recoil mass.

Material

We must contact Nippon Steel & Sumitomo metal for low magnetism stainless steel.

155

2014 Sep. 9

D. Chen, K. Yamamoto

Closed. Three blade springs were delivered on the 1st of October nevertheless we did not visit Shinkosha.

Sapphire monolithic suspension

We must visit Shinkosha after the meeting of Physical Society of Japan.

156

2014 Sep. 9

Control

We should consider the specification of coil magnet actuator on the sapphire mirror (and coating. If the coating covers the mirror surface perfectly, it could be a problem when the magnets are attached). Diffraction loss must be also considered.

157

2014 Sep. 9

D. Chen, K. Yamamoto

Closed. Suzuki-san sent e-mail to MIR on the the 30th of October.

Sapphire monolithic suspension

Zygo will start to evaluate how much the flat cut gives damage on the reflective surface. CRY must provide the design. Kazuhiro tells the polish specification and the direction of a-axis. Hagiwara-san will prepare the design. Takyuki circulates it in CRY. Suzuki-san will send it to MIR as chief of CRY. At that time, he will ask (1)to check what Zygo is going to investigate, (2)to send carbon copy of e-mail to Zygo.

158

2014 Sep. 17

T. Tomaru

Closed. He made (http://wiki.kek.jp/pages/viewpage.action?pageId=37159777).

Overall design

Takayuki makes the wiki page to summarize the important points in the specification list for bidding. For example, we need the room for assembly which is next to the cryostat (and people can stay), tools,..

159

2014 Sep. 17

D. Chen, R. Kumar

Sapphire monolithic suspension

They check the analytical investigation of bending length using Finite Element Method.(#109)

160

2014 Oct. 7

T. Tomaru

Overall design

Takayuki later prepares wiki to write idea about clean booth and so on.

161

2014 Oct. 7

T. Tomaru

Claosed. Takayuki is discussing with detchar 27th of Nov at Osaka City University. ->(#198)

Overall design

CRY and detchar will summarize the environmental monitor and connection and so on.

162

2014 Oct. 7

Overall design

We add two level markers in Y end. At least, one markers must be seen everywhere

163

2014 Oct. 7

Sapphire monolithic suspension

Cold damping for violin mode and so on.

164

2014 Oct. 21

K. Yamamoto

Overall design

We must decide the requirement for magnetism of SolBlack (Barkhausen effect).

165

2014 Oct. 21

N. Kimura, T. Suzuki

Closed. The end of the cryo duct can be moved within +/- 20mm. Kimura-san reported in the chief meeting (27 Oct 2014 http://gwclio.icrr.u-tokyo.ac.jp/lcgtchief/20141027.html)

Overall design

Beam Reducing Telescope duct behind the end cryostat : The error of wedge angle of sapphire mirror is not so small. Thus some “long” hole part around Beam Reducing Telescope. Kimura-san and Suzuki-san (with Torisha) check how much this hole could be long.

166

2014 Oct. 21

Overall design

It is necessary to check the ACTUAL size of tunnel and rooms around Beam Reducing Telescope(whether crane can be near wall and so on).

167

2014 Oct. 21

Sapphire monolithic suspension

Precision in installation: The light transmitted by a sapphire end mirror could not be on the horizontal plane.

168

2014 Oct. 28

T. Tomaru

Overall design

In order to record the progress of installation, interval recorders (for example, http://www.kingjim.co.jp/sp/recolo_ir7/index.html) will be purchased by Takayuki.

169

2014 Oct. 28

Overall design

We must take care of the budget (truck for the heads on the sides of cryostat, front room, payload assembly room, office room for shift, rack)

170

2014 Oct. 28

In fact, length difference of fiber is larger issue. In the worst cases (according to Kazuhiro’s measurement; http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3129), the difference could be about 1 mm. In such a case, shim is necessary.

Sapphire monolithic suspension

1/300 radian gradient problem must be considered (Since the KAGRA baseline has the 1/300 radian gradient, sapphire mirror must be tilted. The stress in the sapphire fiber must be as small as possible.).

171

2014 Nov. 26

Overall design

One Pfeiffer full range gauge is purchased to monitor the pressure in main vacuum chamber of cryostat.

172

2014 Nov. 26

Overall design

CRY is responsible for interlock of Gate Valve. It takes one minute to close valve.

173

2014 Nov. 26

K. Hayama

Kazuhiro Hayama will develop.

Overall design

Development of software to show real time status

174

2014 Nov. 26

T. Suzuki

Overall design

Dummy recoil mass : Some parts will be done by some companies. The other parts will be made by Terashima-san. Suzuki-san organizes.

175

2014 Dec. 16

K. Yamamoto

Sapphire monolithic suspension

We will ask IMPEX how to wash sapphire fibers.

176

2014 Dec. 16

H. Tanaka

Sapphire monolithic suspension

Reconnection of HEM fiber and nail head with Hydroxide Catalysis Bonding(the fiber went from the nail head).

177

2014 Dec. 16

H. Tanaka

Sapphire monolithic suspension

Ettore found a company which has HEM sapphire. We check the cost and delivery date of HEM fiber.

178

2015 Jan. 13

Overall design

Air circulation system for 2nd floor is absolutely necessary.

179

2015 Jan. 13

Tomotada pointed out that the deadline of the submission for joint research with NAOJ is on the 23rd of Jan. It is better to consult with Raffaele or Yoichi in advance.

Overall design

Collaboration between KEK and NAOJ is necessary.

180

2015 Jan. 13

T. Tomaru

Closed. The meeting was held on the 9th of March 2015 at NAOJ. The memo of this meeting (Japanese) is here (http://wiki.kek.jp/display/gw/Discussion+based+on+CAD+drawing).

Overall design

CRY consult VIS control system. Takayuki organizes this meeting.

181

2015 Jan. 13

T. Tomaru

Overall design

Takayuki looks for cart at golf courses.

182

2015 Jan. 13

D. Chen, T. Miyamaoto, Y. Sakakibara, H. Tanaka, K. Yamamoto

Miyomoto-kun, Tanaka-kun, and Kazuhiro made samples under supervision of Dan and Yusuke. Kazuhiro is summarizing the manual.

Sapphire monolithic suspension

Before Dan and Yusuke leave, Hiroki, Takahiro, and Kazuhiro learn how to make Hydroxide Catalysis Bonding, to handle experimental apparatus and ANSYS and so on. Although Dan and Yusuke are busy, we must coordinate our schedule.

183

2015 Jan. 13

K. Yamamoto

Closed. Kazuhiro checked and prefer Nitofix to water glass.->(#190),(#191)

Sapphire monolithic suspension

Dummy sapphire fibers : Photran fibers in KEK and sapphire blocks with hole (we ordered Shinkosha) are combined (water glass or epoxy glue) as dummy sapphire fibers. The practice and jigs for assembly are necessary.

184

2015 Jan. 13

K. Yamamoto

Frame is OK. Maximum load of lab jack must be checked.

Sapphire monolithic suspension

Frame and lab jack for full size sapphire suspension prototype: Kazuhiro will check whether the frame and lab jack for 1/2 dummy payload can be used.

185

2015 Jan. 13

K. Yamamoto

Closed. We will make it (#187)

Sapphire monolithic suspension

Assembly jigs to support the mirror of full size prototype: Size of sapphire bulk for prototype is slightly different from that of the actual KAGRA mirror. We must consider whether the jig for prototype will be prepared or not. First of all, Kazuhiro will check the jig for actual mirror can be used for prototype sapphire bulk.

186

2015 Jan. 20

D. Chen and R. Kumar

Closed.->(#201)

Sapphire monolithic suspension

Dan will tell Rahul details of Dan’s simulation. Crosscheck should be taken care of.

187

2015 Jan. 20

K. Yamamoto

Hagiwara-san wrote. Kazuhiro must check.

Sapphire monolithic suspension

Assembly jigs to support the mirror : Size of sapphire bulk for prototype is slightly different from that of the actual KAGRA mirror. We must prepare it. Kazuhiro will tell Hagiwara-san details later.

188

2015 Jan. 28

H. Tanaka

Sapphire monolithic suspension

Improvement of cryostat with vibration reduction system (H. Tanaka): 350mm fiber should be included. Exchange gas system is necessary.

189

2015 Feb. 17

Overall design

At X-end, there are four hooks. But three of them cannot be used because of falling water. This problem must be fixed.

190

2015 Feb. 17

K. Yamamoto

Sapphire monolithic suspension

Kazuhiro checks the strength (whether it can support 6kg weight or not) of Nitofix for dummy sapphire fiber (photoran straight sapphire fiber and sapphire block with hole from Shinkosha).

191

2015 Feb. 17

K. Yamamoto

Sapphire monolithic suspension

For dummy sapphire fiber (photoran straight sapphire fiber and sapphire block with hole from Shinkosha), the jig to fix the blocks and the fiber before dry must be considered.

192

2015 Feb. 17

Sapphire monolithic suspension

Assembly jigs for full size prototype sapphire suspension is designed and manufactured (We order not only Mechanical Engineering Center of KEK but also mechanical workshop at Institute for Solid State Physics, check and write drawing…).

193

2015 Feb. 17

D. Chen, R. Kumar, T. Miyamaoto, Y. Sakakibara, H. Tanaka, T. Tomaru, K. Yamamoto

Closed. Everything was done.

Overall design

Tanaka-kun, Miyamoto-kun, Takayuki, Rahul, and Kazuhiro learn how to use ANSYS, codes to calculate initial cooling time and vibration isolation of cryogenic payload, Zemax.

194

2015 Mar. 3

R. Kumar

Sapphire monolithic suspension

Ronny proceeds with thermal resistance measurement inside smaller cryostat. Rahul learns.

195

2015 Mar. 3

T. Tomaru, K. Yamamoto

Closed. Ueda-san and Tatsumi-san measured(http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3455).

Sapphire monolithic suspension

Suzuki-san and Takayuki pointed out that it is better to measure the flatness by ourselves although ARD-OPTICS Ltd sends. Takayuki and Kazuhiro will look for who can measure.

196

2015 Mar. 3

Sapphire monolithic suspension

We must practice with larger sample for Hydroxide Catalysis Bonding.

197

2015 Mar. 3

T. Tomaru

Sapphire monolithic suspension

Application software for CAD should be prepared (one space designer license in KEK will be expired at the end of March 2015).

198

2015 Mar. 10

Closed. These monitor system will be installed at X end in the week of 13th of April 2015.

Overall design

Measurement of seismic motion at KAGRA site in long term: For measurement of sound pressure, we look for audio amplifier and microphone. Suzuki-san checks the magnetic flux meter.

199

2015 Mar. 17

T. Tomaru

Overall design

Takayuki asks Yoichi reconsideration about requirement for the aperture of the recoil mass (If the aperture is large, coil magnet actuator should be smaller. It is not so easy).

200

2015 Apr. 7

Overall design

Simple clean booth for front cryostats before October 2016 and the clean booth at the top of Type A must be considered by CRY and VIS, respectively.

201

2015 Apr. 21

Sapphire monolithic suspension

Indium contribution calculation by Dan and Rahul is checked.

202

2015 Apr. 21

Sapphire monolithic suspension

We consider whether we make the slit of sapphire blade spring larger.

203

2015 Apr. 21

T. Tomaru, K. Yamamoto

Sapphire monolithic suspension

Takayuki and Kazuhiro check the stock of sapphire in KEK and ICRR, respectively for sapphire fiber clamp.

204

2015 Jun. 2

Overall design

Dropbox to share the latest CAD drawing (VIS and CRY) is prepared. The memo which describes the contents of CAD is necessary. The link to dropbox is on the KAGRA wiki.

205

2015 Jun. 2

Overall design

The procedure of exchange of dummy load for Type A and cryo payload should be considered. Some devices to support and move payload (in vertical) are necessary.

206

2015 Jun. 2

Overall design

Thermometers near GAS filters are necessary (not only for DetChar, but also VIS itself)

207

2015 Jun. 2

Overall design

Vacuum chamber for BRT : Since there is no drawing, the cylinder whose diameter is 1.2m and height is 2m will be written in design drawings.

208

2015 Jun. 2

Closed. Takahiro shows result; he assumed that length is 250mm, thickness is 2mm, width is 40mm. In this case, appropriate load is 9.73kg weight. Since payload is 120kg in weight, we need 12 blades.->(#214)

Vertical spring

In order to make platform smaller, Takahiro ask Takanori how to design GAS filter. Rahul simulates the smaller (but similar) GAS filter.

209

2015 Jun. 2

Overall design

Rahul investigates new ideas as follow;(1)We would like to reduce of weight Recoil mass of marionetta (40kg->20kg).(2)Recoil mass of intermediate mass (In current design, there is no such mass.)(3)Rigid connection between recoil mass of marionette and that of intermediate mass (as below photo)(4)Rigid connection between marionette and intermediate mass.

210

2015 Jun. 2

Overall design

We must also consider cables of sensors.

211

2015 Jun. 9

Sapphire monolithic suspension

In order to check how Q-values depend on the surface, Kazuhiro later will send the IMPEX monolithic fiber to Takayama-san(National Institute for Fusion Science).

212

2015 Jun. 9

K. Yamamoto

Material

Kazuhiro proceeds with the procurement of low magnetism stainless steel. He will ask whether the increase of magnetism by processing can be reduced by heat treatment.

213

2015 Jun. 16

Overall design

Since it is not easy to carry something along Y arm, maybe we carry from Mozumi entrance. In this case, some cranes or something similar are necessary at Mozumi entrance (Truck from outside cannot enter the KAGRA site !)

214

2015 Jun. 16

Vertical spring

Hagiwara-san checks whether these 12 blade springs (simulated by Takahiro (#)208) can be installed in platform or not.

215

2015 Jun. 16

Vertical spring

Takahiro upload memo about how to design blade spring in GAS (in short what Takanori taught) on KEK wiki.

216

2015 Jul. 8

Sapphire monolithic suspension

Jig for ears on mirror during Hydroxide Catalysis Bonding process. The adjustment along direction which is perpendicular to optical axis is difficult. The end of flat cut is not good reference. Moreover, how to put mark (and remove later) is not an easy issue. Hiroki and Kazuhiro are considering.

217

2015 Jul. 8

Sapphire monolithic suspension

Final version of design drawing of end sapphire mirror will be uploaded on KEK wiki.

218

2015 Jul. 31

Overall design

The acceptable delay of bKAGRA should be considered and discussed.

219

2015 Jul. 31

T. Tomaru

Sapphire monolithic suspension

3 dimension measurement system is necessary to check position of ear after bonding. Takayuki proposed table top one (CMM) and looks for it.

220

2015 Jul. 31

A. Hagiwara

Overall design

Hagiwara-san introduced new CAD drawing of Type A to vacuum chamber. She thinks that check by VIS is necessary. As first step, her drawing is uploaded in dropbox.

221

2015 Jul. 31

Overall design

We observed motion of first floor. So, we must check motion of the second floor. The results of survey on the first and second floors must be connected (via slope or stairs ?). Round connection is better. In any cases, VIS and CRY must consider carefully (not only survey but also installation).

222

2015 Jul. 31

Y. Aso

Overall design

The largest concern of survey is lack of human resource. Outsourcing could be a solution (budget is an issue). Yoichi tells this issue to SEO.

223

2015 Jul. 31

Overall design

We must summarize what we must survey (change of whole tunnel should be measured).

224

2015 Jul. 31

Overall design

Requirements and specifications (length, collimation, and so on) of short optical lever for cryo payload should be summarized.

225

2015 Aug. 4

Overall design

Bending length of metal fiber should be checked

226

2015 Aug. 4

E. Majorana, K. Yamamoto

Overall design

We measure vibration of radiation shield at KAGRA site (X end, probably, June or July 2016). Ettore said that KAGRA can use Luca’s vertical accelerometer and Luca is interested (He can measure). However, Ettore and Kazuhiro found that sensitivity improvement is necessary (Meas. Sci. Technol. 25 (2014) 015103). Ettore checks noise at cryogenic temperature (electric noise is dominated by thermal noise) and performance at Sardinian mine. Ettore also pointed out that the sensitivity is larger when we increase pump current (in the measurement at Toshiba, this current is as small as possible because they are afraid that current can generate heat). We keep touch and exchange information before we start measurement.

227

2015 Aug. 4

K. Yamamoto

Overall design

We measure vibration of radiation shield at KAGRA site (X end, probably, June or July 2016). Kazuhiro will ask Tatsumi-san the status (He has Dan’s horizontal accelerometer now).

228

2015 Aug. 11

Sapphire monolithic suspension

We must decide the distance edges of mirror itself and reflective coating.

229

2015 Aug. 11

Overall design

Ettore proposed particle counter is put in clean booth when somebodies work. It gives much information.

230

2015 Aug. 18

Overall design

We must take care of weight of screws.

231

2015 Sep. 8

Overall design

Preparation of Slow DAQ test at KAGRA site in iKAGRA. CRY intends to check whether DAQ and some thermometers work and joins the preparation of Yoichi and Kazuhiro (H) et al. on next month. CRY must summarize connectors by this preparation. Cables (about 20m length, where they are put (along wall, ceiling, …), ) must be taken care of.

232

2015 Sep. 8

T. Tomaru

Overall design

Takayuki asks Osamu to correct schematic view of Slow DAQ later.

233

2015 Sep. 8

Overall design

We can check output of thermometer in cryostats via ICRR VPN. We must investigate how to access from KEK.

234

2015 Sep. 8

AOS

Overall design

Torisha will deliver two cryo ducts (for end cryostat on the Beam Reducing Telescope side). The first one will arrive on March and the next one will on April or May. So, the first and second one can be test on middle of February and March (or April), respectively (Inhomogeneous SolBlack could be an issue). AOS consider what point must be checked.

235

2015 Sep. 8

AOS

Overall design

AOS checks black coating on low magnetism stainless steel (NSSC-130S from Nippon Steel and Sumitomo Metal).

236

2015 Sep. 8

T. Miyamoto

Overall design

Hagiwara-san revised clamp. But so far, bending length of metal wires is not taken into account. Kazuhiro (Y)’s rough evaluation suggest that it could be several mm. Takahiro will check.

237

2015 Sep. 8

T. Tomaru

Overall design

In order to reduce weight, the Marionetta looks delicate. So, Takayuki checks how much the first resonant frequency is.

238

2015 Sep. 8

A. Hagiwara, T. Tomaru

Overall design

Rahul proposed heavier intermediate mass (to reduce recoil loss). The platform weight could be 60 kg weight. If so, intermediate mass can be heavier. Takayuki and Higiwara-san will check later.

239

2015 Sep. 8

Closed. It is OK if we can adjust the weight of mass within 10% of weight of mass itself (In usual case, about 20kg. So, small masses for adjustment is about 2kg in total.)

Overall design

We discuss the small weight for adjustment of weight of each mass. We must consult with VIS.

240

2015 Sep. 8

Sapphire monolithic suspension

Takayuki mentioned that heat extraction test for ACTUAL KAGRA sapphire suspension (otherwise, we cannot know how much mirror temperature is). But it is not easy … We must consider.

241

2015 Sep. 15

Overall design

Sensor and actuator for vertical (and pitch) motion of intermediate mass is considered.

242

2015 Sep. 15

Overall design

VIS discusses whether (or when) they send their drivers and so on to CRY. Ryutaro sends information of details later.

243

2015 Oct. 14

Sapphire monolithic suspension

We must measure thickness of indium (between nail head and blade spring, and between nail head and sapphire hook (ear).

244

2015 Oct. 14

Sapphire monolithic suspension

Oil in micrometers can be an issue (source of contamination (information from VIS)). We must wash or look for vacuum compatible ones.

245

2015 Oct. 14

Sapphire monolithic suspension

Auto collimator must be taken into account.

246

2015 Nov. 11

R. Kumar

Sapphire monolithic suspension

Rahul prepares design drawing of jack.

247

2015 Dec. 15

Sapphire monolithic suspension

Investigation of water glass between sapphire blade spring and nail head

248

2015 Dec. 24

K. Yamamoto

Sapphire monolithic suspension

Takayuki asked whether we can use clean booth (class 1000) in Advanced measurement experiment building of KEK. Yes, we can. Kazuhiro considers how much area is necessary.

249

2015 Dec. 24

K. Yamamoto

Sapphire monolithic suspension

Four sapphire ears from IMPEX will be delivered tomorrow. Kazuhiro proposed that we ask Ueda-san and Enami-san to measure flatness and geometrical shape and that we provide jig to fix ears for measurement.

250

2016 Jan. 13

K. Yamamoto

Sapphire monolithic suspension

The extra pieces of sapphire fibers must be necessary (risks of breaks) and the budget must be considered.

251

2016 Jan. 13

Sapphire monolithic suspension

CRY will ask MIR to measure geometrical shape of sapphire mirror and flatness of flat cut on barrel surface.

252

2016 Jan. 13

Control

Life time (or change of efficiency) of PD and LED must be taken care of.

253

2016 Jan. 19

R. Kumar

Sapphire monolithic suspension

Rahul summarizes the list of needed item and quotation about sapphire fiber holder

254

2016 Jan. 19

T. Tomaru

Control

Takayuki asks Ryutaro, Yoichi, Osamu, Taknori whether CRY can use digital system of VIS.