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K. Yamamoto and KAGRA collaboration

Institute for Cosmic Ray Research the University of Tokyo

Current status of KAGRACryogenic

16 May 2012Gravitational-Wave Advanced Detector Workshop

@Waikoloa Marriot Resort, Waikoloa Beach, Hawaii, U.S.A.

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Main contributors

K. Yamamoto, R. Takahashi, T. Sekiguchi, Y. Sakakibara, D. Chen, C. Tokoku, M. Kamiizumi,

U. Iwasaki, T. Uchiyama, S. Miyoki, M. Ohashi, T. AkutsuA, H. IshizakiA, A. TakamoriB, T. SuzukiC,

N. KimuraC, T. KumeC, S. KoikeC, K. TsubonoD, Y. AsoD, T. UshibaD, K. ShibataD, N. OhmaeE,

K. SomiyaF, R. DeSalvoG, E. MajoranaH

ICRR.UT, NAOJA,ERI.UTB, KEKC, Phys.S.UTD, E.UTE, S.TITF, Sannio UnivG., INFNH,

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0. Abstract

I must write abstract.

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Contents1.Introduction2.Cryostat3.Cryocooler unit4.Cryogenic payload5.ELiTES6.Future Plan7.Summary

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1. Introduction KAGRA (previously known as: LCGT)

2nd generation interferometer in Japan

Key feature of KAGRA project Cryogenic system : Reduction of thermal noise

I will explain the progress of cryogenic group in the last one year. Now, the first km-scale cryogenic interferometer is being constructed ! 　　　　　　　　　　

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1. Introduction

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3km3km

MozumiY-end Sakonishi

X-end

AtotsuCenter

Vibration isolation system, Cryostat, Cryocooler, Cryogenic payload

Outline of cryostat and cryocoolersFour mirrors of arm cavity will be cooled.

1. Introduction

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Outline of cryostat and cryocoolers

14m in height

Cryostat

Vibration Isolation(Type-A)

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to SAS

View ports

Remote valve unit

4 Low vibration cryocooler unit

Main LASER beam

2.6m~

3.6

m

Cryostat Stainless steel t20mm Diameter 2.6m Height ~3.6m M ~ 10 ton

Cryo-coolers Pulse tube, 60Hz 0.9 W at 4K (2nd) 36 W at 50K (1st)

1. Outline

2. Cryostat

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2. Cryostat 3. Photos (Main body)

at Toshiba Keihin FactoryMain body (Φ2.4m, H3.8m)

Daiwa Shearing Kasuga Factory

Toshiba Keihin Factory

Cryostat Bottom plate SUS 304 t70

Cryostat Service port flange, side cap and tube

Side cap 1970 Tube 1970

Flange 2200Shimoda Flange Aioi Factory

Toshiba Keihin Factory

Cryostat components

Connection port to cryocooler unit

Ribs inside cryostat

Pipes

Welding on the connection port

Toshiba Keihin Factory

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3. Cryocooler unit 1. Outline

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3. Cryocooler unit 2. Photos

14Work progress in clean room with JIS class 7 (US class 10000)

at Jecc Torisha Kawagoe factory

3. Photos

3. Cryocooler

80K thermal conductor

8K thermal conductor Vespel support rod

Assembling in Jecc Torisha Kawagoe factory

Cryocooler itself was made by Sumitomo Heavy Industries.

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3. Cryocooler unit 4. Cooling test

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3. Cryocooler unit 5. Vibration test

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3. Cryocooler unit 5. Vibration test

Displacement sensor

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3. Cryocooler unit 5. Vibration test

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4. Cryogenic payload1. Outline

Sapphire fiber Sapphire

mirror(About 20K)

Shield(8K)

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4. Cryogenic payload

2. Strategy

(1) Experiment of 1/4 cryostat in ICRR to check payload 1/4 means number of cryocooler, not size. (a) How to assemble and install (b) Cooling test (c) Control and damping (2) Other R&D Sapphire fibers to suspend mirror, External vibration via heat links (details are in K. Yamamoto talk on Thursday) and so on

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4. Cryogenic payload

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3. 1/4 cryostat Cryocooler has already arrived at ICRR !

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4. Cryogenic payload 3. 1/4 cryostat Design of 1/4 cryostat is in progress.

Preliminary.

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5. ELiTES ELiTES: ET-LCGT interferometric Telescope Exchange of Scientists Grant for collaboration between KAGRA and ET European 7th Framework Programme Marie Curie action (Mar. 2012 - Feb. 2016)

European people can visit Japan for KAGRA.

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5. ELiTES

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ELiTES consists of four Working Packages.

WP1: Cryogenic payload (E. Majorana)

WP2: Cryogenic mirror (R. Nawrodt) WP3: Cooling system (K. Somiya)

WP4: Organization

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5. ELiTES

Kick off meetings have already been held.

Teleconference every month

General meeting in Japan (this summer or autumn)

First visitor from Europe : This autumn

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6. Future plan Mar. 2013: All cryostats and all cryostats units are assembled. 1/4 cryostat arrives.Apr. 2013 - Sep. 2014: Experiment of 1/4 prototypeApr. 2014 - Sep. 2014 : Installation of cryostats and cryocoolers in Kamioka mineJul. 2014 - Mar. 2015 : Procurement for payload Jul. 2015 - Dec. 2016: Installation and test of cryogenic payload in Kamioka mine Sep. 2017 - Mar. 2018 : Cryogenic interferometer operationApr. 2018 - : Tuning and observation

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Thank you for your attention !

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2. Cryostat 2. Drawing by Toshiba Toshiba starts to make our cryostat.

Cryostat (cryochamber)

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2. Cryostat 2. Drawing by Toshiba Toshiba starts to make our cryostat.

Toshiba

Cryostat (radiation shields)

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2. Cryostat 3. Photos

Ribs inside cryostat

PipesConnection port to cryo-cooler unit

Welding on the connection port

at Toshiba Keihin Factory

Main body (Φ2.4m, H3.8m)

Photos by T.Suzuki

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3. Cryocooler 2. PhotosTorisha made 7 cryocoolers unit and will make 9 units by March 2013. Cryocooler itself was made by Sumitomo Heavy Industries.

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4. Cryogenic duct 1. Outline Cryogenic ducts are along optical axis and next to cryostat.

17 m in length, 0.9 m in diameter, Baffles to prevent propagation of 300 K radiation

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4. Cryogenic duct 2. Design : in progress Details : K. Yamamoto talk tomorrow afternoon

Preliminary.

17 m

Cryostat

~ 1 m

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4. Cryogenic payload 4. Other R&D items (a)How to suspend mirrors using sapphire fibers (b)Vertical spring in cryostat (c)Development and test of sensors, actuators, motors in cryostat (d) Thermal noise (Q measurement of wires and coating and so on) (e) Seismic noise, external vibration noise (vibration of shield, transfer function of heat link) (f) Baffles for scattered light