1. 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

2. 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

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

4. Contents
Introduction
Vibration isolation
Cryogenic payload
Summary

5. 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

6. 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)

7. 1. Introduction
Type-C
Mirror
Stack

8. 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]

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

10. 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)

11. 1. Introduction Schedule for vibration isolation system of KAGRA
iKAGRA (room temperature)
bKAGRA (cryogenic temperature)
Prototype test (ICRR and NAOJ) :
Pre-isolator : –
Type B payload :
Type B :
Assembling (Akeno and Kamioka) :
Standard GASF : –
Installation (Kamioka) :
Type B (for iKAGRA) :
Type A and Type B (for bKAGRA) :

12. 1. Introduction Schedule for cryogenic payload of KAGRA
iKAGRA (room temperature)
bKAGRA (cryogenic temperature)
1/4 cryostat to test payload and R&D :
Design for cryostat and payload : Now
1/4 cryostat installation in ICRR (Kashiwa) :
Experiment of 1/4 cryostat :
Procurement :
Installation :

13. 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 !).

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

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

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

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

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

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

20. 3. Cryogenic payload Preparation for 1/4 cryostat
Design of cryogenic payload is in progress.
Preliminary. 20

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

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

23. 3. Cryogenic payload
Sapphire fibers to suspend sapphire mirrors

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

25. 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

26. 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 !

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

28. 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.

29. Thank you for your attention !

30. 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

31. 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)

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

33. 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

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

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

36. 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

37. 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