1. Cryo-payload Kazuhiro Yamamoto Institute for Cosmic Ray Research
The University of Tokyo
KAGRA face to face meeting
University of Toyama, Toyama, Japan
27 August 2015

2. 0. Abstract Here, I explain (1) Current status and next step
(2) Human resources
for cryogenic payload 2

3. Contents Introduction Sapphire suspension Cryogenic payload
Human resources
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 is a mirror) 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. 2. Sapphire suspension 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.
fiber break
Hydroxide Catalysis Bonding 7

8. 2. Sapphire suspension Current status
We investigated almost all components.
We must construct full size suspension (prototype). 8

9. 2. Sapphire suspension
All sapphire parts for full size prototype have already been delivered. Jigs for assembly is being prepared.
Sapphire cylinder with flat cuts
as dummy mirror
Fibers with nail head
Blade spring
Ears 9 9 9 9 9 9 9 9

10. 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 10 10 10 10 10 10 10

11. 3. Cryogenic payload Outline of cryogenic payload Platform Marionetta
Recoil mass chain
(Thermal noise caused by this part is small)
Marionetta
Intermediate mass
Sapphire Mirror 11 11 11 11 11 11 11

12. 3. Cryogenic payload Outline of cryogenic payload GAS filer Platform
for vertical
vibration isolation
(Mirror chain is
suspended)
Platform
Marionetta
Intermediate mass
Recoil mass chain
Sapphire Mirror 12 12 12 12 12 12 12

13. 3. Cryogenic payload Outline of cryogenic payload Platform
Alignment adjustment system
Platform
Marionetta
Simple system for
high Q-value of sapphire suspension
Intermediate mass
Sapphire Mirror 13 13 13 13 13 13 13

14. 3. Cryogenic payload Outline of cryogenic payload Platform
Sensor and actuator (for control and damping)
Marionetta
Intermediate mass
Sapphire Mirror
Recoil mass chain 14 14 14 14 14 14 14

15. 3. Cryogenic payload Current status A. Hagiwara proceeds with
CAD design drawings. Almost
all parts except for platform
were designed.
Design is based
on discussion
with VIS (9 Mar. 2015)
Platform
Marionetta
Intermediate mass
Mirror
Recoil mass
A. Hagiwara 15 15

16. 3. Cryogenic payload Current status A. Hagiwara proceeds with
CAD design drawings. Almost
all parts except for platform
were designed.
Recoil mass for Marionetta
Recoil mass for intermediate mass
Recoil mass for mirror
A. Hagiwara 16 16

17. 3. Cryogenic payload Next step 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. 17

18. 3. Cryogenic payload 23 kg 150 mm 220 mm
Prototype test of cryogenic payload
Dummy mirror and ears (stainless)
Size and weight are the same as those of KAGRA mirror.
23 kg
150 mm
220 mm
Ears (stainless)
Recoil mass 18 18 18 18 18 18 18

19. 3. Cryogenic payload Prototype test of cryogenic payload
Dummy blade spring
Marionetta
Intermediate mass 19 19 19 19 19 19 19

20. 3. Cryogenic payload
Prototype test of cryogenic payload 20

21. 4. Human resources 8 scientists 2 graduate students (Master course)
3 technical staffs 21

22. KAGRA Cryogenics Group
2015.Jul.25
Takayuki TOMARU
Chief
KEK, Assoc. Prof.
Toshikazu SUZUKI
EO and SEO member
KEK, Senior Fellow
Nobuhiro KIMURA
Cryostat sub-chief
KEK, Assoc. Prof.
Tatsuya KUME
Surveying, Alignment
KEK, Assoc. Prof.
Kazuhiro YAMAMOTO
Cryo-Payload sub-chief
ICRR, Project Assist. Prof.
Suguru TAKADA
Cryogenics
NIFS, Assist. Prof.
Rahul KUMAR
Simulation, Payload
KEK, PD
Kieran CRAIG
Payload
ICRR, PD
Hiroki TANAKA
Cryo-Payload, Q
ICRR, Grad. Student
Takahiro MIYAMOTO
Cryo-Payload
ICRR, Grad. Student
By T. Tomaru
(Revised by K. Yamamoto)
Shinichi TERASHIMA
Machining
KEK, Technical Staff
Ayako HAGIWARA
CAD
KEK, Technical Staff
Iwao MURAKAMI
Welding, Assembly
KEK, Technical Staff 22

23. 4. Human resources
Kieran Craig (from Glasgow) starts to work as postdoc in ICRR on the 1st of August !
Ph.D. defense was on last July !
“Studies of the mechanical dissipation
of thin films for mirrors in interferometric
gravitational wave detectors” 23

24. 5. Summary Full size prototype at KEK and ICRR Cryogenic payload (KEK)
Parts of mirror chain were assembled.
Design of recoil mass chain
and platform is in progress.
Sapphire lop-eared suspension (ICRR)
Assembly jig are being prepared.
2. Human resource
Kieran Craig (Post doc) joins our team ! 24

25. Thank you for your attention !25

26. Backup 26

27. 6. Summary Next step (by Spring 2016)
Full size prototype at KEK and ICRR
2. By Spring 2017
Development of platform (GAS filter)
By Summer 2017
Assembly and test of sapphire suspension
In the second half of 2017
Installation at KAGRA site
One postdoc joins one week later.
KAGRA must take care of KEK people.
Otherwise, they can not work for KAGRA
after 2018. 27

28. 3. Sapphire suspension Schedule By Spring 2016 : Prototype test
of full size sapphire suspension at ICRR
By Autumn 2016 : Procurement
of sapphire parts
By Spring 2017 : Assembly and test
with End sapphire mirrors
By Summer 2017 : Assembly and test
with Front sapphire mirrors
By End 2017 : Installation at KAGRA site 28

29. 3. Cryogenic payload Schedule By Spring 2016 : Prototype test
of full size prototype at KEK
By Spring 2017 : Development of platform
(GAS filter)
By End 2017 : Installation at KAGRA site 29

30. 4. Schedule 30

31. 4. Schedule Full size prototype at KEK and ICRR
Procurement of sapphire parts
Assembly and test
of sapphire part
Development of platform
(GAS filter)
Installation of cryogenic payload 31

32. 4. Schedule Cooling test of cryostat Installation of Type A
Delivery of End sapphire mirrors
Delivery of
Front sapphire mirrors
Installation of cryogenic payload 32 32 32

34. Extremely short commissioning
5. Schedule
Official schedule
iKAGRA observation : By end of 2015
bKAGRA installation and commissioning : By end of 2017
Current budget plan
By March 2016 : One cryogenic payloads
By March 2017 : Three cryogenic payloads (+ spare)
By end of 2017 : Commissioning of bKAGRA
Extremely short commissioning 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