Development of cryogenic payload for KAGRA VI K

Development of cryogenic payload for KAGRA VI K. Yamamoto. A, A. Khalaidovski. A, T. Miyamoto. A, Y. Sakakibara. A, H. Tanaka. A, T. Uchiyama. A, T. Akutsu. B, A. Hagiwara. C, N. Kimura. C, R. Kumar. C, T. Kume. C, S. Koike. C, I. Murakami. C, T. Suzuki. C, S. Terashima. C, T. Tomaru. C, K. Toyoda. C, D. Chen. D, R. De. Salvo. E, E. Majorana. F, L. Naticchioni. F, W. Johnson. G, K. Craig. H, A. Cumming. H, R. Douglas. H, G. Hammond. H , K. Haughian. H, I. Martin. H, P. Murray. H, S. Rowan. H , D. Heinert. I, G. Hofmann. I, J. Komma. I, S. Kroker. I, R. Nawrodt. I, C. Schwarz. I, KAGRA collaboration ICRR. UTA, NAOJB, KEKC, Astro. S. UTD, G H Sannio Univ. E, INFNF, Louisiana Univ. 2015 State March 22 , University of Glasgow , I Jena The. Friedrich-Schiller-Universitaet meeting of Physical Society of Japan @Waseda campus, Waseda University, Shinjuku-ku, Tokyo 1

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0. Abstract Although there are many topics, here, I will explain (1)Activity of cryogenic group at KAGRA site (2)Recent progress of cryogenic payload 3

Contents 1. 2. 3. 4. 5. Introduction Activities at KAGRA site Prototype of cryo payload Sapphire suspension Summary 4

1. Introduction Schematic view of KAGRA interferometer Four mirrors of arm cavity will be cooled in order to reduce thermal noise. 3 k m 3 km Mozumi Y-end Sakonishi X-end Atotsu Center Kamioka mine (Underground site) Vibration isolation system, Cryocooler unit, Cryostat, Cryogenic payload 5

1. Introduction Outline of vibration isolation and cryostat Design drawing without tunnel and cross section Vacuum ducts along laser beam Vibration isolation system (room temperature) 14 m A. Hagiwara Clean booth Cryostat (Here is a mirror) 6

1. Introduction Outline of vibration isolation and cryostat Design drawing with tunnel and cross section Vibration isolation system 2 nd floor A. Hagiwara 14 m Shaft Clean booth Vacuum ducts along laser beam Cryostat (Here is a mirror) 7

1. Introduction Outline of cryostat Cryostat Stainless steel t 20 mm Diameter 2. 6 m Height ~3. 6 m M ~ 10 ton to Vibration isolation system Cryo- payload Mirror View ports Double radiation shield beam R E S A L Main A. Hagiwara 8

1. Introduction Schematic view of cryo-payload Sapphire suspension Pulse tube cryocoolers Cryo-payload Sapphire fiber Sapphire mirror (About 20 K) 9

2. Activities at KAGRA site KAGRA tunnel excavation was finished one year ago. What did cryogenic group at KAGRA site in the last half year ? (N. Kimura(leader), T. Suzuki, T. Tomaru, T. Kume, D. Chen, Y. Sakakibara, H. Tanaka. T. Miyamoto) 10

2. Activities at KAGRA site (1)All four cryostats were carried in the site (18 Nov. 2014). All of them were fixed on the ground (26 Feb. 2015). 11

2. Activities at KAGRA site (2) No leaks were found (both end cryostats). < Leak test > KAGRA requirement < 1 x 10 -10 Pa*m 3/sec Detector background 1 x 10 -12 Pa*m 3/sec 12

2. Activities at KAGRA site (3) Cryocoolers and cryo duct are connected to cryostat (center room, by the beginning of April). Cryostat Cryo duct Cryocooler (In total, four cryocoolers) Y front cryostat 13

2. Activities at KAGRA site (4) Seismic motion measurement Seismic motion is as small as we expected ! We have plan for long observation (K. Hayama talk). T. Tomaru, 3 rd ELi. TES meeting, https: //events. egogw. it/indico/get. File. py/access? contrib. Id=11&session. Id=3&res. Id=0&material. Id=slides&conf. Id=16 14

3. Prototype of cryo payload Two kinds of full size prototypes for development Those are our important next step ! (1)Cryo-payload with dummy sapphire suspension This is almost same as the actual cryo-payload. Parts of “sapphire” suspension is a dummy (made from metal). (2)Sapphire lop-eared suspension A part of cryo-payload Main sapphire mirrors are included. All parts are made from sapphire. Current status : Procurement is in progress. Some parts were delivered ! 15

3. Prototype of cryo payload (1)Cryo-payload with dummy sapphire suspension Latest (not final) CAD design drawings by A. Hagiwara Still many items have no CAD design drawings …. Platform Intermediate masses Mirror Recoil mass A. Hagiwara 16

3. Prototype of cryo payload (1)Cryo-payload with dummy sapphire suspension Local sensor and actuator to adjust angle and position of sapphire mirror Cryogenic test is necessary (T. Miyamoto talk). A. Hagiwara 17

3. Prototype of cryo payload (1)Cryo-payload with dummy sapphire suspension Intermediate masses We ordered VIC (http: //www. vic-int. co. jp/) and the parts were delivered. Dummy mirror and Recoil mass Processing in Mechanical Engineering Center of KEK delivered. 18

3. Prototype of cryo payload (1)Cryo-payload with dummy sapphire suspension Dummy mirror and ears (stainless) 23 kg 150 mm Size is the same as KAGRA mirror. Recoil mass 220 mm Ears (stainless) 19

3. Prototype of cryo payload (1)Cryo-payload with dummy sapphire suspension Intermediate masses Upper Dummy blade spring Lower 20

3. Prototype of cryo payload (1)Cryo-payload with dummy sapphire suspension Assembly T. Miyamoto 21

3. Prototype of cryo payload (1)Cryo-payload with dummy sapphire suspension Assembly T. Miyamoto 22

3. Prototype of cryo payload (2)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. Prototype of cryo payload (2)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. Prototype of cryo payload (2)Sapphire lop-eared suspension When fibers are broken, they can be removed ! Hydroxide Catalysis Bonding 25

3. Prototype of cryo payload (2)Sapphire lop-eared suspension Processing of two flat cut on barrel surface IMPEX (Germany), ARD-OPTICS Ltd (Armenia) Sapphire cylinder (Shinkosha) as dummy mirror Size is similar to that KAGRA mirror. It was delivered ! 26

3. Prototype of cryo payload (2)Sapphire lop-eared suspension Blade spring (Shikosha) We have 3 pieces. 2 pieces are coming soon. Ears (IMPEX, ARD-OPTICS) were delivered ! 27

3. Prototype of cryo payload (2)Sapphire lop-eared suspension Four sapphire fibers with nail heads : IMPEX They will be delivered soon ! Q-values should be measured. Development of measurement system: H. Tanaka talk Julius Komma joined measurement (supported by ELi. TES). 28

4. Sapphire suspension R&D for components (1)Current status R&D for fundamental items Large strength (to suspend sapphire mirror) Small thermal resistance (to extract heat absorbed in mirror) Small mechanical loss (smaller thermal noise) Almost all items have already been checked ! Mainly by Dan Chen (and ELi. TES guests) Here highlights and open issues are introduced. 29

4. Sapphire suspension (2)Thermal noise Calculation (D. Chen) based on measurement by himself Thermal noise is smaller than KAGRA sensitivity ! 30

4. Sapphire suspension (2)Thermal noise Calculation (D. Chen) based on measurement by himself Rahul Kumar considered the loss around blade spring clamp carefully (his talk). 31

4. Sapphire suspension (3)Blade spring Compensation of differences between sapphire fiber length R. Kumar, GWADW 2014 (http: //www. gravity. ircs. titech. ac. jp/GWADW 2014/slide/Rahul_ Kumar. pdf) Shinkosha 32

4. Sapphire suspension (3)Blade spring Sapphire blade spring 6 kg mass (1/4 of KAGRA mirror) Nail head of sapphire fiber D. Chen, J. Komma, H. Tanaka, Y. Liu Four blade springs can support one KAGRA mirror ! Resonant frequency of vertical mode Measurement : 14. 3 Hz, Calculation : 14. 4 Hz 33

4. Sapphire suspension (3)Blade spring Drift with load D. Chen, H. Tanaka 34

4. Sapphire suspension (3)Blade spring D. Chen, H. Tanaka 35

4. Sapphire suspension (4)Indium bonding Indium on both ends of sapphire fiber When fibers are broken, they can be removed. Melting point of indium : 157 degree Celsius Dan confirmed that indium has enough small thermal resistance and mechanical loss. How is indium between sapphire parts melted? D. Chen, H. Tanaka ELi. TES guests (J. Komma, D. Vine, M M. Herrera, K. Haughian, P. Murray, R. Nawrodt) 36

4. Sapphire suspension (4)Indium bonding How is indium between sapphire parts melted? Halogen lamp looks promising. We need not to attach anything on sapphire parts. This lamp emits near infrared light transmitted by sapphire. 37

4. Sapphire suspension (4)Indium bonding Halogen lamp works ! (simple blocks) Indium We must consider the case with real suspension. Sapphire block David Vine, Mariela Masso Herrera, Karen Haughian, Peter Murray, Ronny Nawrodt (supported by ELi. TES) 38

Ph. D. theses Dr. Yusuke Sakakibara A Study of Cryogenic Techniques for Gravitational Wave Detection Cooling time of payload and cyro duct to reduce 300 K radiation propagation Dr. Dan Chen Study of a cryogenic suspension system for the gravitational wave telescope KAGRA Sapphire suspension and vibration from cooling system 39

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. 40

5. Summary Activities at KAGRA site All four cryostats were fixed at KAGRA site. Cryocoolers and cryo ducts are being connected to cryostats. Prototype of cryo payload Procurement is in progress. Some parts were delivered ! Sapphire suspension Sapphire blade spring can support KAGRA mirror. For indium bonding, halgen lamp can be useful. 41

5. Summary Presentaions after this summary talk Rahul Kumar : design and thermal noise estimation of sapphire suspension Takahiro Miyamoto : Development of tilt adjustment system Hiroki Tanaka : Measurement of Q-values of sapphire fibers 42

Thank you for your attention ! 43

3. Sapphire suspension Sapphire fibers with nail heads Quality check under collaboration with ET (ELi. TES) Q-value Measurement in Glasgow, Jena, Rome and Tokyo Thermal conductivity Measurement in Jena, Rome and Tokyo Strength Measurement in Glasgow 44

3. Sapphire suspension Sapphire fibers with nail heads Latest summary of Q and thermal conductivity Moltech IMPEX KAGRA requirement Q-value 107 at 20 K Thermal Conductivity 3000 at 20 K [W/m/K] 1*106 -6*106 5000 -6000 5000 IMPEX fibers satisfy the KAGRA requirement. 45

3. Sapphire suspension Bonding between sapphire fibers and sapphire mirror Diffusion bonding Hydroxide Catalysis Bonding (Ad. LIGO and Virgo) If fibers are broken, bonding parts must be taken apart … Candidates : Indium, Optical contact, Screws Test (in progress or near future plan) Strength test (tensile and shear) : KEK Thermal resistance : ICRR Mechanical dissipation : Jena and Glasgow (ELi. TES) 46

3. Sapphire suspension Bonding between sapphire fibers and sapphire mirror Hydroxide Catalysis Bonding Rebecca reported in ELi. TES meeting (Dec. 2013). https: //events. ego-gw. it/indico/conference. Other. Views. py? view=standard&conf. Id=7 47

3. Sapphire suspension Bonding between sapphire fibers and sapphire mirror Hydroxide Catalysis Bonding (Rebecca Douglas[Glasgow], GWADW 2013). Strength (about 60 MPa) measured by her is 10 times larger than those of previous papers. T. Suzuki et al. , Journal of Physics; Conference Series 32(2006)309. A. Dari et al. , Classical and Quantum Gravity 27(2010)045010. Rebecca Douglas and Karen Haughian stayed in Japan in the last autumn. Rebecca reported in ELi. TES meeting (Dec. 2013). https: //events. ego-gw. it/indico/conference. Other. Views. py? view=standard&conf. Id=7 48

7. For future Some items for future research (not perfect list) (a)Investigation material properties (Q, thermal conductivity, strength etc. ) of coating, fiber and so on. (b)Sapphire bonding, Sapphire fiber clamp (c)Control and damping scheme Actuators and sensors at cryogenic temperature (d) Mechanical and thermal simulation for payload (e) Vertical spring in cryostat (f) Reduction of initial cooling time Thermal resistance of clamp. . (g) Baffles for scattered light in radiation shield (h) Assembly procedure 49

8. Summary Cryostat : Assembly is in progress. Cooling test is coming soon. Cryogenic duct : Optimum position of 5 buffles Future work : scattered light Cryocooler unit : Cooling test and vibration measurement : OK Cryogenic payload Preparation for 1/4 cryostat to check payload performance is in progress. Current main R&D topics Inital cooling time, Sapphire fiber with nail head, Coating mechanical loss, Vibration of shield 50

2. Issues (1)How to assemble Details of construction, clean room …. (2)Strength Tensile strength, development of clamp, sapphire bonding … (3)Control and damping system to reduce fluctuation and instability Actuators (what and where), resonant mode (frequency and Q) and so on 51

2. Issues (4)Cooling Temperature of mirror (below 20 K), initial cooling time, heat resistance of clamp … (5)Noise Thermal noise, vibration via vibration isolation system and heat links … 52

5. Other topics Metal blade spring for vertical vibration isolation Cryogenic test is in progress in Kashiwa. Q measurement of wires to suspend masses (except for mirror) is in progress (tungsten, Cu. Be, …) Measurement of magnetism of mass and black coating Control system Cryogenic tests are in progress. Stepping motor to adjust angle of masses : KEK Optical sensor (a candidate to monitor mass motion) : ICRR 53

4. Sapphire fibers After Yusuke left …. Clamp for IMPEX fibers in Jena 54

4. Sapphire fibers Profile measurement in Glasgow 55

5. Sapphire suspension Sapphire fibers with nail heads Q measurement in Jena 56