Development of vibration isolation systems for LCGT VII K. Yamamoto, R. Takahashi, T. Sekiguchi, Y. Sakakibara, C. Tokoku, M. Kamiizumi, U. Iwasaki, T. Uchiyama, S. Miyoki, M. Ohashi, T. AkutsuA, H. IshizakiA, D. ChenA, A. TakamoriB, T. SuzukiC, N. KimuraC, S. KoikeC, K. TsubonoD, Y. AsoD, T. UshibaD, K. ShibataD, N. OhmaeE, K. SomiyaF, R. DeSalvoG, E. MajoranaH, E. HennesI, J. Van den BrandI, A. BertoliniIJ, N.A. LockerbieK, LCGT collaboration ICRR.UT, NAOJA,ERI.UTB, KEKC, Phys.S.UTD, E.UTE, S.TITF, Sannio UnivG., INFNH, NikefI, AEIJ, University of StrathclydeK At first, thank you for giving a chance talk here. In fact, I have been in Trento in 2002, eight years ago. I am happy because I can visit here again. OK, shall we start ? This is the title of my talk of today. Gravitational wave and detectors. 2012 March 24 The meeting of Physical Society of Japan @Kwansei Gakuin University, Nishinomiya, Hyogo

Development of vibration isolation systems for KAGRA VII K. Yamamoto, R. Takahashi, T. Sekiguchi, Y. Sakakibara, C. Tokoku, M. Kamiizumi, U. Iwasaki, T. Uchiyama, S. Miyoki, M. Ohashi, T. AkutsuA, H. IshizakiA, D. ChenA, A. TakamoriB, T. SuzukiC, N. KimuraC, S. KoikeC, K. TsubonoD, Y. AsoD, T. UshibaD, K. ShibataD, N. OhmaeE, K. SomiyaF, R. DeSalvoG, E. MajoranaH, E. HennesI, J. Van den BrandI, A. BertoliniIJ, N.A. LockerbieK, LCGT collaboration ICRR.UT, NAOJA,ERI.UTB, KEKC, Phys.S.UTD, E.UTE, S.TITF, Sannio UnivG., INFNH, NikefI, AEIJ, University of StrathclydeK 2012 March 24 The meeting of Physical Society of Japan @Kwansei Gakuin University, Nishinomiya, Hyogo 2

0. Abstract Progress of development of vibration isolation system, which includes cryogenic payload, for KAGRA in the last half year

Contents Introduction Vibration isolation Cryogenic payload Summary

1. Introduction KAGRA (previously known as: LCGT) 2nd generation interferometric 　　　　　　　　　　　gravitational wave detector in Japan Key features of KAGRA project Silent underground site (Kamioka) : 　　　Small seismic motion reduced requirements for vibration isolation system. Cryogenic system : Reduction of thermal noise 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　and so on

1. Introduction Type-A IP + GASF (5 stage) + Payload (23kg, cryogenic) Type-B IP + GASF (3 stage) + Payload (10kg/20kg) Type-C Stack + Single/Double-pendulum (～1kg)

1. Introduction Type-C Mirror Stack

Type-B Pre-isolator Filter chain Payload Top filter [Filter0] Inverted Pendulum (IP) Filter chain Standard GASF Filter1 (Filter1~3 in Type-A) Bottom Filter (BF) Intermediate Mass (IM) Intermediate Recoil Mass (IRM) Payload Test Mass (TM) Recoil Mass (RM) Optical Bench [Breadboard]

1. Introduction Type A and Cryo payload 14m in height Vibration Isolation (Type A) Cryostat Cryogenic mirror 9

Y. Sakakibara’s talk (in this session) 1. Introduction Cryo payload Shield (8K) Sapphire fiber Sapphire mirror (20K) Y. Sakakibara’s talk (in this session)

1. Introduction Schedule for vibration isolation system of KAGRA iKAGRA (room temperature) - 2015.12 bKAGRA (cryogenic temperature) 2016.1 - Prototype test (ICRR and NAOJ) : - 2014.3 Pre-isolator : 2011.7 – 2012.9 Type B payload : 2012.7 - 2013.6 Type B : 2013.1 - 2014.3 Assembling (Akeno and Kamioka) : 2012.4 - 2014.9 Standard GASF : 2012.4 – 2012.9 Installation (Kamioka) : 2014.4 - 2016.5 Type B (for iKAGRA) : 2014.4 - 2015.6 Type A and Type B (for bKAGRA) : 2015.5 - 2016.5

1. Introduction Schedule for cryogenic payload of KAGRA iKAGRA (room temperature) - 2015.12 bKAGRA (cryogenic temperature) 2016.1 - 1/4 cryostat to test payload and R&D : - 2014.9 Design for cryostat and payload : Now 1/4 cryostat installation in ICRR (Kashiwa) : 2013.3 Experiment of 1/4 cryostat : 2013.4 - 2014.9 Procurement : 2014.10 - 2015.6 Installation : 2015.8 - 2016.12

2. Vibration isolation Complete system Prototype test (Pre-isolator) in Kashiwa (ICRR) Complete system Details of experimental test will be reported by T. Sekiguchi (next talk !).

2. Vibration isolation Pre-isolator Prototype test (Pre-isolator) in Kashiwa (ICRR) Pre-isolator Pre-isolator load 14

2. Vibration isolation Standard GASF (prototype) (production) Prototype test (Pre-isolator) in Kashiwa (ICRR) Standard GASF (prototype) (production) 15

2. Vibration isolation Prototype test (Pre-isolator) in Kashiwa (ICRR) Digital system has already been installed (O. Miyakawa’s talk in this session).

2. Vibration isolation Storage & Assembling Delivered apparatus will be assembled in clean booths and stored in Akeno observatory (ICRR), Yamanashi.

2. Vibration isolation Akeno Lucca (Italy) 19 standard GASF’s from Italy and clean booths arrived. We will start assembling soon. Akeno Lucca (Italy)

3. Cryogenic payload Preparation for 1/4 cryostat Design of 1/4 cryostat is in progress. Preliminary. 19

3. Cryogenic payload Preparation for 1/4 cryostat Design of cryogenic payload is in progress. Preliminary. http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=570 20

3. Cryogenic payload Preparation for 1/4 cryostat Themal and mechanical simulation of payload (S. Koike, Y. Sakakibara, and T. Sekiguchi) 21

3. Cryogenic payload Cryocooler has already arrived at ICRR ! Preparation for 1/4 cryostat (C. Tokoku) Cryocooler has already arrived at ICRR ! 22

3. Cryogenic payload Sapphire fibers to suspend sapphire mirrors

3. Cryogenic payload Test sample (T. Uchiyama) Sapphire fibers to suspend sapphire mirrors Test sample (T. Uchiyama)

3. Cryogenic payload Sapphire fibers to suspend sapphire mirrors Sapphire fibers from MolTech GmbH (Germany) Length = 350 mm diameter = 1.8 mm Almost as needed in bKAGRA. Need to check the quality. 25

3. Cryogenic payload Baffle for the (large angle) scattered light Design from Mike Smith – Caltech (support from LIGO and U.S. National Science Foundation ) Needs suspension inside radiation shield !

3. Cryogenic payload Digital system for temperature monitor Discussion is in progress.

4. Summary Vibration isolation Prototype test in Kashiwa : pre-isolator (Sekiguchi and Miyakawa’ talk) Assembling of Standard GASF in Akeno is started soon. Cryogenics payload Design of the 1/4 cryostat and payload are in progress. Cryocooler for 1/4 cryostat and test samples of sapphire fibers arrived. Baffle in cryostat and digital system are being discussed.

Thank you for your attention !

4. Summary Plan for next half year Vibration isolation Prototype test : pre-isolator and payload Assembling in Akeno : Standard GASF Cryogenics payload Design of the 1/4 cryostat and payload

2. Issues (1)How to assemble Details of construction, clean room …. (2)Strength Tensile strength, development of clamp, … (3)Control system Actuators (what and where), resonant mode (frequency and Q)

2. Issues (4)Cooling Temperature of mirror, initial cooling time, heat resistance … (5)Noise Thermal noise, vibration via heat links …

4. Summary Cryogenic payload : One of key features of LCGT project Cryogenic part of seismic isolation system Cryostat installation in ICRR (Kashiwa) ~2013.3 (Check of cryostat system) Check of cryogenic payload in ICRR Preparation is in progress. (1)Thermal simulation (2)Sapphire fiber-mirror connection (3)Simulation of effect of external vibration (with heat link) (4)Thermal noise

5. Future work (1)How to assemble Details of construction, clean room …. (2)Control system Actuators (what and where), resonant mode (frequency and Q)

Type-B Inverted pendulum Top filter 2-stage GASF Mirror

Schedule along roadmap 1. Introduction Schedule along roadmap 2011 2012 2013 2014 2015 2016 Standard GASF Prototype test in NIKHEF/ICRR Procure Assembling in Akeno Pre-isolator in ICRR Type-B payload in NAOJ in Kamioka Installation Type-A SAS in the site ETM ITM Type-B SAS in TAMA SRM PRM Stack iKAGRA operation

Configuration Type-A: IP + GASF (5 stage) + Payload (23kg, cryogenic) Type-B: IP + GASF (3 stage) + Payload (10kg/20kg, room temp.) Type-C: Stack + Single/Double-pendulum (~1kg) Chamber iKAGRA bKAGRA ITMX, ITMY, ETMX, ETMY Type-A IAOX, IAOY, EAOX, EAOY Type-B Payload on Stack (for ITM/ETM) Type-C (for AO) BS, PR2, PR3 Type-B PRM, SRM, SR2, SR3 MCF, MCE, MMT PD, BRTX, BRTY