1. Status of KAGRA Cryogenics II
Kazuhiro Yamamoto, Kieran Craig, Takaaki Kajita, Takahiro Miyamoto, Hiroki Tanaka, Ayako HagiwaraA, Nobuhiro KimuraA, Rahul KumarA, Toshikazu SuzukiA, Takayuki TomaruA, Ayako UedaA, Takafumi UshibaB, Junko KasuyaC, Suguru TakadaD, Sadakazu HainoE, Yuki InoueE,
Ettore MajoranaF, Helios VoccaG,
KAGRA Cryogenics Subgroup
ICRR, AKEK, BPhys.S.UT, CTITEC, DNIFS, EAcademia Sinica, FINFN Rome, GINFN Perugia
2016 September 22
The meeting of Physical Society of Japan
@Kihana campus, University of Miyazaki, Miyazaki, Miyazaki 1 1 1 1

2. 0. Abstract Here, I explain Current status of (1) Cryostats at site
(2) Cryogenic payload 2

3. Contents
Introduction
Cryostats at site
Cryogenic payload
Summary 3

4. 1. Introduction Schematic view of KAGRA interferometer
Four mirrors of arm cavity will be cooled.
3km
3km
Mozumi
Y-end
Sakonishi
X-end
Kamioka mine
(Underground site)
Atotsu
Center
Vibration isolation system (Type A), Cryocooler unit, Cryostat, Cryogenic payload 4 4 4 4 4 4 4 4

5. Vibration isolation system Vacuum ducts along laser beam
1. Introduction
Outline of vibration isolation and cryostat
Design drawing with tunnel and cross section
2nd floor
A. Hagiwara
Vibration isolation system
(room temperature)
14 m
Shaft
Clean booth
Vacuum ducts along laser beam
Cryostat
(Here the mirror is) 5 5 5

6. 1. Introduction Schematic view of cryo-payload Sapphire suspension
Pulse tube cryocoolers
Pulse tube cryocoolers
Sapphire fiber
Cryo-payload
Sapphire mirror (About 20K)

7. 1. Introduction Schematic view of cryo-payload Sapphire suspension
Pulse tube cryocoolers
Pulse tube cryocoolers
Cryo duct

8. 2. Cryostats at site
We must conduct cooling test of all cryostats by March 2017.
So far, at both ends, missions for assembly and connection were over.
Leak check is current main mission at both ends.
Mission for two cryostats in center room will be started on November.

9. 2. Cryostats at site
So far, at both ends, missions as below were over.
Installation of duct shield and 80K cryocooler units
A. Hagiwara
Cryostat
(Here the mirror is)

10. 2. Cryostats at site
So far, at both ends, missions as below were over.
Installation of duct shield and 80K cryocooler units

11. 2. Cryostats at site
So far, at both ends, missions as below were over.
(2) Connection 4K cryocoolers unit to each cryostats
to SAS
Outline of cryostat
4 Low vibration
cryocooler unit
Remote
valve unit
S. Koike 11

12. 2. Cryostats at site
So far, at both ends, missions as below were over.
(2) Connection 4K cryocoolers unit to each cryostats
to SAS

13. 2. Cryostats at site
So far, at both ends, missions as below were over.
(3) Connection of 900 cross duct
A. Hagiwara
Cryostat
(Here the mirror is) 13

14. 2. Cryostats at site
So far, at both ends, missions as below were over.
(3) Connection of 900 cross duct 14

15. 2. Cryostats at site
So far, at both ends, missions as below were over.
(3) Connection of 900 cross duct 15

16. 3. Cryogenic payload Outline of vibration isolation and cryostat
Pulse tube cryocoolers
Pulse tube cryocoolers
Cryo-payload 16 16 16 16 16 16 16

17. 3. Cryogenic payload Outline of vibration isolation and cryostat
Platform
Recoil mass for Marionette
Recoil mass for intermediate mass
Recoil mass for mirror
A. Hagiwara 17 17

18. 3. Cryogenic payload
The first cryogenic payload has already been delivered and assembled !
Performance test (adjustment and control system, measurement of transfer function) is in progress or being prepared. 18 18 18 18 18 18 18 18 18

19. 3. Cryogenic payload Outline of cryogenic payload Mirror chain
Platform
Recoil mass chain
Marionette
Intermediate mass
Thermal noise caused by recoil mass chain is small.
Sapphire Mirror 19 19 19 19 19 19 19

20. 3. Cryogenic payload Outline of cryogenic payload GAS filer Platform
for vertical
vibration isolation
(Mirror chain is
suspended)
Platform
Marionette
Intermediate mass
Sapphire Mirror 20 20 20 20 20 20 20

21. 3. Cryogenic payload Outline of cryogenic payload Platform
Alignment adjustment system
Platform
Marionette
Simple system for
high Q-value of sapphire suspension
Intermediate mass
Sapphire Mirror 21 21 21 21 21 21 21

22. 3. Cryogenic payload Outline of cryogenic payload Platform
Sensor and actuator (for control and damping)
Marionette
Intermediate mass
Sapphire Mirror 22 22 22 22 22 22 22

23. 3. Cryogenic payload Sapphire lop-eared suspension
“Sapphire monolithic
lop-eared suspension”
One of the most important
parts of KAGRA :
Main sapphire mirrors
are included.
All parts are made
from sapphire. 23

24. 3. Cryogenic payload Blade spring Fiber with nail head on both ends
Sapphire lop-eared suspension
Blade spring
(compensation of fiber length difference)
Fiber with nail head on both ends
Flat cut
Nail head of fiber
Mirror
Ear
A. Hagiwara

25. 3. Cryogenic payload Sapphire lop-eared suspension
Indium bonding on both nail heads of fiber
When fibers are broken, they can be removed !
Hydroxide Catalysis Bonding
between ear and mirror

26. 3. Cryogenic payload
We expect that all of main parts of cryogenic payload will be delivered by March 2017 as schedule.
Two sapphire mirrors for end stations (End Test Mass) will be delivered for assembly of cryogenic payload on February 2017.
September- December 2017 : Installation at both end stations
We must strongly proceed with prototype test and development. 26 26 26 26 26 26 26 26

27. 3. Cryogenic payload
Current hot topics (presentations in this session)
Design of control system
for cryogenic payload
T. Miyamoto’s talk 27 27 27 27 27 27 27 27

28. 3. Cryogenic payload
Current hot topics (presentations in this session)
R. Kumar’s talk 28 28 28 28 28 28 28 28

29. 3. Cryogenic payload
Current hot topics (presentations in this session)
Assembly sapphire suspension
(Bonding between ears and mirror)
K. Craig’s talk
(K. Yamamoto presents on behalf of him) 29 29 29 29 29 29 29 29

30. 3. Cryogenic payload
Current hot topics (presentations in this session)
Heat load test with simplified (one fiber) prototype
Sapphire blade spring
H. Tanaka’s talk
Sapphire fiber
6kg sapphire mass
(1/4 of KAGRA mirror)
D. Chen 30 30 30 30 30 30 30 30

31. 3. Cryogenic payload
Current hot topics (presentations in this session)
Measurement of Q-values of sapphire blade spring
T. Ushiba’s talk 31 31 31 31 31 31 31 31

32. 4. Summary Cryostats at site
Cooling test of all four cryostats by March 2017
Assembly and connection at both ends were over.
Leak test at both ends is in progress.
Cryogenic payload
Procurement of main parts by March 2017
Installation at both ends
on September-December 2017
We must strongly proceed !
Hottest topics will be presented by next 5 speakers. 32

33. Thank you for your attention !33

34. Backup 34

35. 35

36. 3. Cryogenic payload Outline of cryostat Cryogenic payload Mirror
to SAS
Cryogenic payload
Cryostat
Stainless steel t20mm
Diameter 2.6m
Height ~3.6m
M ~ 10 ton
Mirror
View ports
4 Low vibration
cryocooler unit
Cryo-coolers
Pulse tube, 60Hz
0.9 W at 4K (2nd)
36 W at 50K (1st)
Main LASER beam
Remote
valve unit
S. Koike

37. 3. Cryogenic payload Outline of vibration isolation and cryostat
Heat link (pure Al)
Heat link (pure Al)
Pulse tube cryocoolers
Pulse tube cryocoolers
Cryo-payload 37 37 37 37 37 37 37

38. 3. Cryogenic payload Design A. Hagiwara proceeds with
Without recoil chain
Design
A. Hagiwara proceeds with
CAD design drawings. Almost
all parts except for platform
were designed.
Design is based
on discussion
with Vibration Isolation
subgroup of KAGRA.
Marionette
Platform
Intermediate mass
Mirror
A. Hagiwara 38 38

39. 3. Cryogenic payload Prototype test of cryogenic payload
Two differences from actual one
Platform does NOT include
GAS filter.
Mirror and fibers are NOT made from sapphire, but metal. 39

40. 3. Cryogenic payload Prototype test of cryogenic payload
Without recoil chain
Prototype test of cryogenic payload
Marionette, Intermediate mass,
Dummy mirror, Recoil mass
For (dummy mirror) has already
been delivered.
Marionette
Intermediate mass
Dummy Mirror (and recoil mass)
A. Hagiwara 40 40

41. Acknowledgement 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 Feb. 2016)
European people can visit Japan
for KAGRA. 41 41 41

42. 2. Sapphire suspension
All sapphire parts for full size prototype have already been delivered (IMPEX and Shinkosha).
Sapphire cylinder with flat cuts
as dummy mirror
Fibers with nail head
Blade spring
Ears 42 42 42 42 42 42 42 42

43. 2. Sapphire suspension One fiber prototype 6kg mass (copper)
(1/4 of KAGRA mirror)
Sapphire blade spring
Nail head of
sapphire fiber
Support frame 43

44. 2. Sapphire suspension One fiber prototype Sapphire blade spring
Dummy Cu wire
Sapphire mass
D. Chen, J. Komma, H. Tanaka, Y. Liu

45. 2. Sapphire suspension One fiber prototype
Now, it is in cryostat and first (primitive)
cooling test is in progress. 45