Status of KAGRA Cryogenics II Kazuhiro Yamamoto Kieran

Status of KAGRA Cryogenics II Kazuhiro Yamamoto, Kieran Craig, Takaaki Kajita, Takahiro Miyamoto, Hiroki Tanaka, Ayako Hagiwara. A, Nobuhiro Kimura. A, Rahul Kumar. A, Toshikazu Suzuki. A, Takayuki Tomaru. A, Ayako Ueda. A, Takafumi Ushiba. B, Junko Kasuya. C, Suguru Takada. D, Sadakazu Haino. E, Yuki Inoue. E, Ettore Majorana. F, Helios Vocca. G 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 1

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

Contents 1. 2. 3. 4. Introduction Cryostats at site Cryogenic payload Summary 3

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

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

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

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

2. Cryostats at site We must conduct cooling test of all cryostats by spring of 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. 8

2. Cryostats at site So far, at both ends, missions as below were over. (1) Installation of duct shield and 80 K cryocooler units A. Hagiwara Cryostat (Here the mirror is) 9

2. Cryostats at site So far, at both ends, missions as below were over. (1) Installation of duct shield and 80 K cryocooler units 10

2. Cryostats at site So far, at both ends, missions as below were over. to SAS (2) Connection 4 K cryocoolers unit to each cryostats Outline of cryostat 4 Low vibration cryocooler unit Remote valve unit S. Koike 1111

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

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

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

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

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

3. Cryogenic payload Outline of vibration isolation and cryostat Platform Marionette and recoil mass Intermediate mass and recoil mass Mirror and recoil mass A. Hagiwara 17

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

3. Cryogenic payload Outline of cryogenic payload Mirror chain Platform Recoil mass chain Thermal noise caused by recoil mass chain is small. Marionette Intermediate mass Sapphire Mirror http: //gwdoc. icrr. u-tokyo. ac. jp/cgi-bin/private/Doc. DB/Show. Document? docid=2106 19

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

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

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

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

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

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 25

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.

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

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

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

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)

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 6 kg sapphire mass (1/4 of KAGRA mirror) D. Chen

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

4. Summary Cryostats at site Cooling test of all four cryostats by spring of 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. 33

Thank you for your attention ! 34

Backup 35

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3. Cryogenic payload Outline of cryostat to SAS Cryogenic payload Cryostat Stainless steel t 20 mm Diameter 2. 6 m Height ~3. 6 m M ~ 10 ton Mirror View ports M Cryo-coolers Pulse tube, 60 Hz 0. 9 W at 4 K (2 nd) 36 W at 50 K (1 st) 4 Low vibration cryocooler unit ai n LA SE S. Koike R be a Remote valve unit m 37

3. Cryogenic payload Outline of vibration isolation and cryostat Heat link (pure Al) Pulse tube cryocoolers Cryo-payload 38

3. Cryogenic payload Without recoil chain Design A. Hagiwara proceeds with CAD design drawings. Almost all parts except for platform were designed. Design is based Platform on discussion with Vibration Isolation subgroup of KAGRA. Intermediate mass Mirror Marionette A. Hagiwara 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. 40

3. Cryogenic payload Prototype test of cryogenic payload Without recoil chain Marionette, Intermediate mass, Dummy mirror, Recoil mass For (dummy mirror) has already been delivered. Marionette Intermediate mass Dummy Mirror (and recoil mass) A. Hagiwara 41

Acknowledgement ELi. TES: ET-LCGT interferometric Telescope Exchange of Scientists Grant for collaboration about cryogenic between KAGRA and ET European 7 th Framework Programme Marie Curie action (Mar. 2012 - Feb. 2016) European people can visit Japan for KAGRA. 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 43

2. Sapphire suspension One fiber prototype Sapphire blade spring 6 kg mass (copper) (1/4 of KAGRA mirror) Nail head of sapphire fiber Support frame 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. 46