1111 K. Yamamoto, R. Takahashi, K. Ono, T. Sekiguchi, Y. Sakakibara, C. Tokoku, M. Kamiizumi, U. Iwasaki, E. Hirose, A. Khalaidovski, T. Uchiyama, S. Miyoki, M. Ohashi, T. Akutsu A, H. Ishizaki A, T. Suzuki B, N. Kimura B, S. Koike B, K. Tsubono C, Y. Aso C, T. Ushiba C, K. Shibata C, D. Chen D, N. Ohmae E, K. Somiya F, R. DeSalvo G, E. Majorana H, L. Naticchioni H, W. Johnson I, A. Cumming J, R. Douglas J, K. Haughian J, I. Martin J, P. Murray J, S. Rowan J, G. Hofmann K, C. Schwarz K, D. Heinert K, R. Nawrodt K, KAGRA collaboration ICRR.UT, NAOJ A, KEK B, Phys.S.UT C, Astro.S.UT D, E.UT E,S.TIT F, Sannio Univ. G, INFN H, Louisiana State Univ. I, University of Glasgow J, Friedrich-Schiller-Universitaet Jena K Development of cryogenic payload for KAGRA III 2013 September 22 The meeting of Physical Society of University, Kochi, Kochi

2 0. Abstract Although there are many topics, but here, I will explain (1)Experiment in cooling test of KAGRA cryostat (2)1/4 cryostat (for performance test) (3)Monolithic sapphire suspension

3 Contents 1.Introduction 2.KAGRA cryostat 3.1/4 cryostat 4.Sapphire suspension 5.Summary

44 1. Introduction 444 3km Mozumi Y-end Sakonishi X-end Atotsu Center Vibration isolation system, Cryocooler unit, Cryostat, Cryogenic payload Schematic view of KAGRA interferometer Four mirrors of arm cavity will be cooled. Kamioka mine (Underground site)

55 Cryogenic mirror Cryostat Vibration Isolation Outline of vibration isolation and cryostat 1. Introduction 14 m

6 to SAS View ports Remote valve unit 4 Low vibration cryocooler unit Main LASER beam Cryostat Stainless steel t20mm Diameter 2.6m Height ~3.6m M ~ 10 ton Cryo-coolers Pulse tube, 60Hz 0.9 W at 4K (2nd) 36 W at 50K (1st) Outline of cryostat Cryogenic payload Mirror 20K 1. Introduction S. Koike

7 Main topics Experiment using KAGRA cryostat Initial cooling time of cryogenic payload Radiation shield vibration 1/4 cryostat Performance test of cryogenic payload Sapphire monolithic suspension Key component of KAGRA 1. Introduction

KAGRA cryostats have already been assembled ! at Toshiba Keihin Product Operations 8 2. KAGRA cryostat

Cooling test for all four KAGRA cryostats January 2013 – April 2013 Three of them were move to a warehouse near Kamioka on the 27 th and 28 th of July. Cooling test for the 3rd cryostat July 2013 – August KAGRA cryostat

Three cryostats were move to a warehouse near Kamioka on the 27 th and 28 th of July KAGRA cryostat

Three of cryostats were move to a warehouse near Kamioka on the 27 th and 28 th of July KAGRA cryostat

Three of cryostats were move to a warehouse near Kamioka on the 27 th and 28 th of July KAGRA cryostat

13 Experiments in cooling test of KAGRA cryostat Experiment 1 : Initial cooling time of cryogenic payload This initial cooling time should be short. Yusuke Sakakibara and Kenji Ono reported in previous talks. Experiment 2 : Measurement of shield vibration This vibration causes motion of mirrors and scattered light noise. Dan Chen and Luca Naticchioni developed cryogenic accelerometer. 2. KAGRA cryostat

14 Experiment 2 : Measurement of shield vibration Dan Chen (horizontal motion) 2. KAGRA cryostat Analysis for sensitivity is in progress. After cooling down 10K

15 Experiment 2 : Measurement of shield vibration Luca Naticchioni (vertical motion) 2. KAGRA cryostat Analysis for sensitivity is in progress. After cooling down 10K

16 Cryogenic payload is not a simple system. We need cryostat to test cryogenic payload performance. KAGRA cryostat is not appropriate for test. Cleanness must be kept 1/4 cryostat will be prepared in Kashiwa campus. 1/4 means number of cryocooler, not size. It will be delivered on the end of September. 3. 1/4 cryostat

17 Initial cooling test with liquid nitrogen (Jecc Torisha) : 30th Aug Delivery : 27th of Sep Vacuum chamber : 1.2 m in diameter, 1.6 m in height 3. 1/4 cryostat 1.5hours 100K

18 4. Sapphire suspension 18 Sapphire monolithic suspension Sapphire mirror suspended by sapphire fibers. Key component of KAGRA We need (a)Drilled sapphire mirror (b)Sapphire fibers with nail heads Preliminary

19 4. Sapphire suspension 19 Drilled sapphire bulk We ordered Shinkosha (test sample). It will be delivered on the end of September. KAGRA mirrors : 220 mm in diameter

20 4. Sapphire suspension 20 Drilled sapphire bulk We ordered Shinkosha (test sample). It will be delivered on the end of September. Latest status (19 th of Sep. 2013)

21 4. Sapphire suspension 21 Test sample (T. Uchiyama) Sapphire fibers with nail heads are necessary to suspend mirrors.

22 MolTech GmbH (Germany) and IMPEX HighTech GmbH (Germany) have already delivered ! 4. Sapphire suspension Sapphire fibers with nail heads Although the size is similar to that of KAGRA, quality check is necessary.

4. Sapphire suspension 23 Sapphire fibers with nail heads Quality check under collaboration with ET (ELiTES) Q-value Measurement in Glasgow, Jena, Rome and Tokyo Thermal conductivity Measurement in Jena, Rome and Tokyo Strength Measurement preparation in Glasgow

24 Latest summary 4. Sapphire suspension Moltech IMPEX KAGRA requirement Q-value *10 6 5*10 6 at 20K Thermal Conductivity at 20K [W/m/K] Although these results are promising, further investigation is necessary. Sapphire fibers with nail heads

25 4. Sapphire suspension Thermal conductivity of four IMPEX fibers Enough high conductivity But Q-values was not measured. Aleksandr Khalaidovski Ronny Nawrodt

26 4. Sapphire suspension Q-values of IMPEX fibers (high thermal conductivity) Measurement is in progress at Rome. Dan Chen, Ettore Majorana

27 4. Sapphire suspension Measurement is in progress at Rome. Dan Chen, Ettore Majorana Q-values of IMPEX fibers (high thermal conductivity)

28 4. Sapphire suspension 28 Assembled sapphire monolithic suspension Performance of assembled monolithic sapphire pendulum must be checked. Before that, sapphire bulk is suspended by sapphire fibers using indium as thermal and mechanical contact (some kinds of “glue” instead of bonding) between sapphire bulk and fibers. We will investigate performance and obtain expertise for the monolithic pendulum test as first step.

29 4. Sapphire suspension 29 Assembled sapphire monolithic suspension A. Khalaidovski designed the frame for this first step. This frame was delivered.

30 5. Summary KAGRA cryostat Experiments in cooling test : Initial cooling time of payload Previous talks by Y. Sakakibara and K. Ono Radiation shield vibration Measurement was finished. Analysis for sensitvity is in progress. D. Chen and L. Naticchioni 1/4 cryostat to check cryogenic payload will be delivered by the end of September.

31 5. Summary Sapphire monolithic suspension Drilled bulk will be delivered on end of September. Experiments for sapphire fiber are in progress but the results are promising. We are preparing the first step experiment of monolithic sapphire suspension. A. Khalaidovski, R. Nawrodt, D. Chen, E. Majorana

32 Acknowledgement 32 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.

33 C. Tokoku

34 Thank you for your attention !

35 6. Human resources 35 Japanese graduate students visited (or will visit) Europe. Yusuke Sakakibara (October 2012 – December 2012) Investigation for coating and sapphire fibers (Glasgow and Jena) ET meeting, Hannover, December (Takanori Sekiguchi (January 2013 – March 2013) Investigation for vibration isolation (Amsterdam) ) Dan Chen (September 2013 – October 2013) Investigation for sapphire fiber (Rome)

36 6. Human resources 36 Visitors supported by ELiTES in the last half year Christian Schwarz, Gerd Hofmann, Ronny Nawrodt (Jena) Automatic systems to measure Q-values and thermal conductivity of sapphire fibers Luca Naticchioni, Maurizio Perci, Ettore Majorana (Rome) Measurement of KAGRA radiation shield at cryogenic temperature (Kieran Craig (Glasgow) Measurement of coating mechanical dissipation)

37

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39 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 7. For future

40 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

41 8. Summary ELiTES has already started and supports the development of KAGRA cryogenic system. If you want to join our mission, let us know.

42 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

43 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 …

44 Test 2 : Heat load test How much is temperature with extra heat load ? We can derive extra heat load from temperature. Examples for extra heat load Scattered light by mirror Heat absorption in mirror 300 K radiation through holes for main beam 44 Cooling test in Toshiba

45 Cooling test in Toshiba 45 Test 2 : Heat load test 45 Pulse tube cryocoolers Heater and thermometer Sapphire mirror

Cooling test in Toshiba 46 Test 2 : Heat load test 46 2 W 5 W 10 W 0 W Scatted power is 5 W when scattered loss on the mirror surface is 10 ppm.

Cooling test in Toshiba 47 Test 2 : Heat load test 47 Pulse tube cryocoolers Heater and thermometer Sapphire mirror

Cooling test in Toshiba 48 Test 2 : Heat load test 48 4 W 10 W 0 W According to our design, temperature should be below 8 K when heat absorption in mirror is 1 W.

/4 cryostat Bid (for parts of 1/4 cryostat) was opened ! (Jecc Torisha) Discussion for final design is in progress. Preliminary and not latest version.

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

51 Profile measurement in Glasgow 4. Sapphire fibers

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

53 Thermal conductivity measurement in Jena 5. Sapphire suspension Sapphire fibers with nail heads

54 Latest summary 5. Sapphire suspension Crystal axis Ribbon ? Sapphire fibers with nail heads

55 Outline of vibration isolation and cryostat 55 2 Pulse tube cryocoolers Pulse tube cryocoolers Baffles Cryoduct Outer shield (80K) Inner shield (8K) Vacuum chamber (300K)

Outline of vibration isolation and cryostat 56 Pulse tube cryocoolers Heat link (pure Al) Sapphire mirror (About 20K) Heat link (pure Al) Sapphire fiber

57 Cooling test of KAGRA cryostat in Toshiba 57 Test 1 : Initial cooling time of ratidation shield How long does it take to cool shield ? Test 2 : Heat load test How much is temperature with extra heat load? C. Tokoku et al., Proceedings of CEC/ICMC 2013 (2EPoE1-03) K. Yamamoto et al., Opening a new era for the astrophysics: The future detectors of gravitational waves (19 April 2013) bin/DocDB/ShowDocument?docid= KAGRA cryostat

58 Test 1 : Initial cooling time The result (2 weeks) is similar to our expectation. There is no large unexpected heat invasion and resistance. 2. KAGRA cryostat Cooling test of KAGRA cryostat in Toshiba

59 Two items for cryoduct (1)300K radiation though this cryo duct must be small. (2)Scattered light noise by this duct should be small. Not only scattered light itself but also vibration of cryo duct should be small. Preparation for experiment is in progress. Yusuke Sakakibara will explain details later. 3. Cryoduct

60 5. Sapphire suspension 60 Drilled sapphire bulk We ordered Shinkosha (test sample). It will be delivered on the end of September. 30 th of July 2013

61 Construction is in progress (Jecc Torisha). Support frame inside radiation shield

62 Construction is in progress (Jecc Torisha). Radiation shield

63 Construction is in progress (Jecc Torisha). Vacuum chamber : 1.2 m in diameter, 1.6 m in height 4. 1/4 cryostat

64 5. Sapphire suspension 64 Bonding between sapphire fibers and sapphire mirror Investigation of Hydroxide Catalysis Bonding is in progress in Glasgow. (Rebecca Douglas, GWADW2013). 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) Plan : Measurement of thermal resistance and so on.

65 6. Human resources 65 Fresh persons Dr. Aleksandr Khalaidovski from Hannover, June 2013-May 2014 Sapphire monolithic suspension (Dr. Fabián Erasmo Peña Arellano from Birmingham, May 2013 – April 2016 Cryogenic sensor) Dr. Rahul Kumar from Glasgow, October 2013 – September 2014 Simulation and development of payload