kazuhiro yamamoto institute for cosmic ray research (icrr) the university of tokyo

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Kazuhiro Yamamoto

Institute for Cosmic Ray Research (ICRR)the University of Tokyo

KAGRA face to face meeting 　　　Institute for Cosmic Ray Research, The University of Tokyo,

Kashiwa, Chiba, Japan14 February 2014

Cryo-payloadSuspension structure

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Contribution

R. Takahashi, K. Ono, T. Sekiguchi, Y. Sakakibara, C. Tokoku, M. Kamiizumi, U. Iwasaki, E. Hirose, A. Khalaidovski, R. Kumar,

T. Uchiyama, S. Miyoki, M. Ohashi, K. Kuroda, T. AkutsuA, H. IshizakiA, F. E. Peña ArellanoA, T. SuzukiB, N. KimuraB, S. KoikeB, T. KumeB,

K. TsubonoC, Y. AsoC, T. UshibaC, K. ShibataC, D. ChenD, N. OhmaeE, K. SomiyaF, R. DeSalvoG, E. MajoranaH, L. NaticchioniH, W. JohnsonI,

A. CummingJ, R. DouglasJ, K. HaughianJ, I. MartinJ, P. MurrayJ, G. HammondJ, S. RowanJ , G. HofmannK, C. SchwarzK, D. HeinertK,

R. NawrodtK, S. GotoL, M. TanakaL, S. IokaM, K. NakamotoM, H. NezukaM, KAGRA collaboration

ICRR.UT, NAOJA, KEKB, Phys.S.UTC, Astro.S.UTD, E.UTE,S.TITF, Sannio Univ.G, INFNH, Louisiana State Univ.I , University of GlasgowJ,

Friedrich-Schiller-Universitaet JenaK, Jecc TorishaL, Toshiba Keihin Product OperationsM, KAGRA collaboration

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0. Abstract

Although there are many topics, here,I will explain

(1)Schedule(2)Overall design(3)Monolithic sapphire suspension(4)Heat links

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Contents1.Introduction2.Schedule3.Overall design4.Sapphire suspension5.Heat links6.ELiTES activity7.Summary

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1. Introduction

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3km3km

MozumiY-end Sakonishi

X-end

AtotsuCenter

Vibration isolation system, Cryocooler unit, Cryostat, Cryogenic payload

Schematic view of KAGRA interferometerFour mirrors of arm cavity will be cooled.

Kamioka mine (Underground site)

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Outline of vibration isolation and cryostat

1. Introduction

14 m

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Cryogenic mirror

Cryostat

Vibration Isolation


1. Introduction

14 m

8

to SAS

View ports

Remote valve unit

4 Low vibration cryocooler unit

Main LASER beam

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)

Outline of cryostatCryogenic

payload

Mirror

1. Introduction

S. Koike


99999

Pulse tube cryocoolers



Heat link (pure Al)

Sapphire mirror (About 20K)

Heat link (pure Al)

Sapphire fiber

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1. Introduction Schematic view of cryogenic payload

http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=2106

Platform

Intermediate Recoil Mass

Recoil Mass

Intermediate Mass

Test Mass (sapphire mirror)

Design is in progress.Details should be changed.

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1. Introduction Outline of cryogenic payload


Intermediate Mass

Intermediate Recoil Mass

Recoil MassTest Mass (sapphire mirror)

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1. Introduction Outline of cryogenic payload in radiation shield


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1. Introduction “Sapphire monolithic suspension”

One of the most importantparts of KAGRA : Main sapphire mirrorsare included.

All parts are made from sapphire.Details should be changed.

Mirror

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2. Schedule

End of 2017 : Cryogenic interferometer operationThis is the significant milestone of KAGRA.

Delivery of cryogenic payloadBy March 2015, One payloadBy March 2016, Three payloads

“Official plan”

For sapphire monolithic suspension, so aggressive !

The suspensions will be improved step by step.Initial phase suspension before final phase one is necessary.

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2. Schedule “Initial phase” Larger thermal noise but more feasible First cryogenic payload (2015) is a “Initial phase”.

R&D for final phase should be in progress at the same time.　　 Otherwise, thermal noise can not be reduced. We must do our best for three payloads as final phase (2016).

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2. Schedule

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Although thermal noise is large, it should be cooled (heat load test is necessary).

It should be as simple as possible (budget and human resources).

It can be replaced by final phase sapphire monolithic suspension later.

“Initial phase”

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2. Schedule

17171717

(1)No bonding, but screws, indium, cradle(2)Thick tungsten wires (they transfer heat)

There are some ideas for “Initial phase”

Indium

R&D for these plans must be finished and we select an idea by May 2014.

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3. Overall design

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Not sapphire suspension, but cryogenic payload in total

Takanori Sekiguchi and Eiichi Hirose visited Stanford (December 2013) to discuss overall design with control system.

Design and discussion are in progress.

Preliminary design documenthttp://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=2106

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3. Overall design

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E. Hirose organizes team to design the first cryogenic payload (Member : E. Hirose, T. Sekiguchi, R.Takahashi, R. Kumar). Dead line is June 2014. Short meeting every morning

Some figures in 1. Introduction are brought by this team.

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4. Sapphire suspension

20202020

Sapphire monolithic suspension

R&D for components are in progress.

There are a lot of items.Here,(1)Sapphire fiber(2)Sapphire blade spring(3)Sapphire bondingare introduced.

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Test sample (T. Uchiyama)

Sapphire fibers with nail heads are necessary to suspend mirrors.


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MolTech GmbH (Germany) and IMPEX HighTech GmbH (Germany) have already delivered !

Sapphire fibers with nail heads


MolTech GmbH

IMPEX HighTech GmbH

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Quality check under collaboration with ET (ELiTES) Q-value Measurement in Glasgow, Jena, Rome and Tokyo Thermal conductivity Measurement in Jena, Rome and Tokyo Strength Measurement in Glasgow


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Latest summary of Q and thermal conductivity

Moltech IMPEX KAGRA requirement

Q-value 107 1*106 5*106

at 20K -6*106

Thermal Conductivity 3000 5000 5000at 20K [W/m/K] -6000


IMPEX fibers satisfy the KAGRA requirement.


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Q of IMPEX fiber (D. Chen)



Requirement : 5*106

https://events.ego-gw.it/indico/conferenceOtherViews.py?view=standard&confId=7

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Thermal conductivity of IMPEX fiber



arXiv: 1401.2346

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Paper about thermal conductivity measurement was submitted to Classical and Quantum Gravity.


arXiv: 1401.2346


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Strength test in Glasgow Fiber suspended weight. Moreover, weight was swung or pulled.


15kg test hang

Broken jointed end

Broken jointed end


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Strength test in Glasgow Fiber suspend weight. Moreover, weight was swung or pulled.G. Hammond reported in ELiTES meeting (December 2013).https://events.ego-gw.it/indico/conferenceOtherViews.py?view=standard&confId=7

Safety factor derived from measurement : 3 - 16


Broken jointed end


E. Majorana will visit Glasgow in this month and try strength test.

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Although we investigated fibers with round nail heads …Flat surfaces are necessary for bonding.New fibers with square nail head (IMPEX) is coming soon (end of February) !


Our plan for these fibers Surface flatness check (less than /10 (=630nm)) Measurement of thermal conductivity and Q


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Sapphire fibers are thick (1.6 mm in diameter) for heat transfer.Stretch by sapphire mirror weight (23kg) : 21 m

If difference between length of 4 fibers are larger than 21 m, there is no tension in one fiber !

Blade spring is necessary.

Sapphire blade spring


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Sapphire blade spring (design is in progress)


Vertical resonant frequency : 17.4 Hz

Max. stress : 159 MPa

Bending breaking stress :300 MPa

(G. Hammond reported in ELiTES meeting

https://events.ego-gw.it/indico/conferenceOtherViews.py?view=standard&confId=7)

R. Kumar 46 mm

90 mm

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Bonding between sapphire fibers and sapphire mirrorHydroxide Catalysis Bonding (AdLIGO and Virgo)

If fibers are broken, bonding parts must be taken apart …Candidates : Indium, Optical contact, Screws

Test (in progress or near future plan) Strength test (tensile and shear) : KEK Thermal resistance : ICRR Mechanical dissipation : Jena and Glasgow (ELiTES)


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Bonding between sapphire fibers and sapphire mirrorHydroxide Catalysis Bonding


Si

Si Si Si O

O O O

OH OH OH OH

Bulk Silica

Bonding solution with lots of free OH - ions

OH - ions from the bonding s olution fill any open bonds on the surface

OH - ions form weak bonds with surface Si atoms

Bonds be tween the Si atoms and the bulk weaken due to the extra OH - ions bonding to the Si atom

Si

Si Si O

O O O

OH

Bulk Silica

Bonding solution with lots of free OH - ions

OH OH

OH

Si(OH) 5 -

Silicate molecule breaking away from the bulk and into the bonding solution

SiO2 SiO2

Bond

OH

H

Si

i

OH

H

OH

H

H2O

OH H O Si

OH

OH

H

Si

OH

OH

H2O

OH H O Si

OH

OH

H2O

OH H O


Rebecca reported in ELiTES meeting (Dec. 2013).

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Bonding between sapphire fibers and sapphire mirror Hydroxide Catalysis Bonding (Rebecca Douglas[Glasgow], GWADW2013). Strength (about 60 MPa) measured by her is 10 times larger than those of previous papers. T. Suzuki et al., Journal of Physics; Conference Series 32(2006)309. A. Dari et al., Classical and Quantum Gravity 27(2010)045010.

Rebecca Douglas and Karen Haughian stayed in Japan in the last autumn. Rebecca reported in ELiTES meeting (Dec. 2013). https://events.ego-gw.it/indico/conferenceOtherViews.py?view=standard&confId=7


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Rebecca Douglas and Karen Haughian HCB Shear strength test (Strength vs crystal direction)

Preliminary



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Next HCB shear strength test is in progress.



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IndiumIf fibers are broken, bonding parts must be taken apart …

Indium is one of candidates.

Hot welding Foil or evaporation (thickness: <20 m) are prepared and heat is applied.

When bonding parts are taken apart, heat and acid are applied.


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We are preparing sample (KEK) …


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R&D for integration of components

One fiber prototype

Full prototype



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Heat link (pure Al)Heat link (pure Al)

5. Heat links

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5. Heat links

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Heat links must be thick and short as heat path. However they must be thin and long as vibration path !

Dan Chen reports vibration via heat link in the next talk.

Yusuke Sakakibara explains initial cooling time of cryogenic payload at the first talk in this afternoon.

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6. ELiTES activities

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

European people can visit Japan for KAGRA.

484848


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A total of 25 visitors supported by ELiTES in 2013 Note : Short stay for meeting is not counted.

Germany (A total of 8 persons) Jena (A total of 6 persons), Hannover (2 persons)Netherlands NIKHEF (2 persons)United Kingdom Glasgow (3 persons)Italy (A total of 12 persons) Rome (3 persons), Sannio (A total of 9 persons)

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ELiTES in 2014 has already started !

Ettore Majorana (Rome) : Last week ! Discussion for cryogenic payload and vibration isolation

Ronny Nawrodt and Stefanie Kroker (Jena) arrived this morning ! Cryogenic experiment

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7. SummarySchedule Schedule is quite aggressive. We need initial phase suspension. Later it will be replaeced by final phase one. Design of initial phase suspension should be finished by next May.Overall design Discussion with Stanford Small team for design (short meeting every morning) Preliminary design documenthttp://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=2106

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7. SummarySapphire suspension Research and development for components (quality checks of fibers, design of blade spring, test for many kinds of bonding) are finished or in progress. New fibers with square nail heads will be delivered at the end of February.Heat link Dan Chen (vibration) and Yusuke Sakakibara (initial cooling time) report later. ELiTES A total of 25 visitors in 2013. So far, 3 visitors in 2014.

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Thank you for your attention !

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Some items for future research (not perfect list)

(a)Investigation material properties (Q, thermal conductivity, strength etc.) of coating, fiber and so on.(b)Sapphire bonding, Sapphire fiber clamp(c)Control and damping scheme Actuators and sensors at cryogenic temperature(d) Mechanical and thermal simulation for payload(e) Vertical spring in cryostat(f) Reduction of initial cooling time Thermal resistance of clamp .... (g) Baffles for scattered light in radiation shield(h) Assembly procedure

7. For future

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8. SummaryCryostat : Assembly is in progress. Cooling test is coming soon.Cryogenic duct : Optimum position of 5 buffles Future work : scattered lightCryocooler unit : Cooling test and vibration measurement : OKCryogenic payload Preparation for 1/4 cryostat to check payload performance is in progress. Current main R&D topics Inital cooling time, Sapphire fiber with nail head, Coating mechanical loss, Vibration of shield

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2. Issues

(1)How to assemble Details of construction, clean room ….

(2)Strength Tensile strength, development of clamp, sapphire bonding …

(3)Control and damping system to reduce fluctuation and instability Actuators (what and where), resonant mode (frequency and Q) and so on

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2. Issues

(4)Cooling

Temperature of mirror (below 20 K), initial cooling time, heat resistance of clamp …

(5)Noise

Thermal noise, vibration via vibration isolation system and heat links …

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After Yusuke left …. Clamp for IMPEX fibers in Jena

4. Sapphire fibers

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Profile measurement in Glasgow

4. Sapphire fibers

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Q measurement in Jena

5. Sapphire suspensionSapphire fibers with nail heads

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6060606060

2 Pulse tube cryocoolers

2 Pulse tube cryocoolers


Baffles Cryoduct

Outer shield(80K)

Inner shield(8K)

Vacuum chamber

(300K)

kazuhiro yamamoto institute for cosmic ray research (icrr) the university of tokyo

Documents

importantparts of kagra

kagra collaboration

main sapphire mirrorsare

significant milestone

university of glasgowj

toncryocoolers pulse

face meetinginstitute

sannio univ