1. 1 Kazuhiro Yamamoto, Dan Chen, Hiroki Tanaka, Takahiro Miyamoto Institute for Cosmic Ray Research (ICRR) the University of Tokyo KAGRA face to face meeting Hongo campus, The University of Tokyo, Tokyo, Japan 6 February 2015 Cryo-payload design

2. 2 Contribution K. Yamamoto, A. Khalaidovski, T. Miyamoto, Y. Sakakibara, H. Tanaka, T. Uchiyama, T. Akutsu A, S. Zeidler A, A. Hagiwara B, N. Kimura B, R. Kumar B, T. Kume B, S. Koike B, I. Murakami B, T. Suzuki B, S. Terashima B, T. Tomaru B, K. Toyoda B, D. Chen C, R. DeSalvo D, E. Majorana E, L. Naticchioni E, W. Johnson F, K. Craig G, A. Cumming G, R. Douglas G, G. Hammond G, K. Haughian G, I. Martin G, P. Murray G, S. Rowan G, D. Heinert H, G. Hofmann H, J. Komma H, S. Kroker H, R. Nawrodt H, C. Schwarz H, KAGRA collaboration ICRR.UT, NAOJ A, KEK B, Astro.S.UT C, Sannio Univ. D, INFN E, Louisiana State Univ. F, University of Glasgow G, Friedrich-Schiller-Universitaet Jena H

3. 3 0. Abstract Although there are many topics, here, Kazuhiro Yamamoto will explain recent progress and status of (1)Design (of prototype) of cryo-payload (2)Fabrication (of prototype) of cryo-payload Some items of R&D will be reported by young researchers, Dan Chen and two fresh persons, Hiroki Tanaka and Takahiro Miyamoto (Prof. Kajita group).

4. 4 Contents 1.Introduction 2.Design of “prototype” 3.Fabrication of “prototype” 4.R&D items 5.Summary

5. 55 1. Introduction 555 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)

6. 66 Outline of vibration isolation and cryostat 1. Introduction A. Hagiwara (KEK) proceeds with CAD design drawing. Here, outline of vibration isolation and cryostat is introduced with her drawing (not final version).

7. 77 Outline of vibration isolation and cryostat 14 m 1. Introduction Vacuum ducts along laser beam Cryostat (Here is a mirror) Vibration isolation system (room temperature) Clean booth Design drawing without tunnel and cross section A. Hagiwara

8. 88 Outline of vibration isolation and cryostat 14 m 1. Introduction Vacuum ducts along laser beam Vibration isolation system Clean booth Design drawing with tunnel and cross section Cryostat (Here is a mirror) 2 nd floor Shaft A. Hagiwara

9. 9 to Vibration isolation system View ports Main LASER beam Cryostat Stainless steel t20mm Diameter 2.6m Height ~3.6m M ~ 10 ton Cryo- payload Mirror 1. Introduction Outline of cryostat Double radiation shield A. Hagiwara

10. 10 View ports Main LASER beam Sapphire Mirror 1. Introduction Outline inside cryostat Baffle for wide angle scattered light to Vibration isolation system A. Hagiwara Cryo- payload

11. 11 Two kinds of full size prototypes for development 11 2. Design of “prototype” Those are our important next step ! (1)Sapphire lop-eared suspension A part of cryo-payload Main sapphire mirrors are included. All parts are made from sapphire. (2)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).

12. One of the most important parts of KAGRA : Main sapphire mirrors are included. All parts are made from sapphire. Mainly, D. Chen proceeds with investigation. Details appear on the next Tuesday (10th of Feb) in ELiTES meeting (40 min his talk !). 12 D. Chen 2. Design of “prototype” (1)Sapphire lop-eared suspension

13. 13 A. Hagiwara Ear Nail head of fiber Fiber with nail head on both ends Blade spring (compensation of fiber length difference) Mirror Flat cut 2. Design of “prototype” (1)Sapphire lop-eared suspension

14. 14 Hydroxide Catalysis Bonding D. Chen fiber break 2. Design of “prototype” (1)Sapphire lop-eared suspension Bonding between sapphire parts

15. (2)Cryo-payload with dummy sapphire suspension 15 Pulse tube cryocoolers Sapphire suspension Sapphire mirror (About 20K) Sapphire fiber 2. Design of “prototype” Schematic view of cryo-payload Cryo-payload

16. (2)Cryo-payload with dummy sapphire suspension 16 Pulse tube cryocoolers Heat link (pure Al) Sapphire mirror (About 20K) Sapphire fiber 2. Design of “prototype” Schematic view of cryo-payload

17. 17 Latest (not final) CAD design drawings by A. Hagiwara 17 A. Hagiwara Mirror Platform (with vertical spring) 2. Design of “prototype” (2)Cryo-payload with dummy sapphire suspension

18. 18 Mirror Recoil mass “Two” intermediate masses Upper part includes angle adjustment system. A.Hagiwara wrote CAD design drawing of these parts ! 2. Design of “prototype” (2)Cryo-payload with dummy sapphire suspension A. Hagiwara Lower part is simple for high Q of sapphire suspension.

19. 19 Still many items have no CAD design drawings …. (a)Platform (Vertical metal spring) Investigation of CuBe for this spring is in progress at KEK (T. Tomaru et al.). (b)Recoil mass for intermediate mass 19 2. Design of “prototype” (2)Cryo-payload with dummy sapphire suspension A. Hagiwara

20. Still many items have no CAD design drawings …. (c)Local sensor and actuator to adjust angle and position Cryogenic test is necessary (T. Miyamoto). (Short and long optical levers are also adopted) 20 2. Design of “prototype” A. Hagiwara (2)Cryo-payload with dummy sapphire suspension

21. Still many items have no CAD design drawings …. (d)Heat links to cool payload (and extra pendulum for vibration isolation) (e)Baffle (and suspension) 21 A. Hagiwara 2. Design of “prototype” (2)Cryo-payload with dummy sapphire suspension

22. 22 Fabrication for prototypes must be in progress ! (1)Sapphire lop-eared suspension All sapphire parts will be delivered by end of next March. (2)Cryo-payload with dummy sapphire suspension (Dummy) mirror, recoil mass, and intermediate mass will be delivered by end of next March. 3. Fabrication of “prototype”

23. 23 A. Hagiwara 2 ears 4 fibers 4 blade springs 1 sapphire bulk 2 Flat cuts (1)Sapphire lop-eared suspension 3. Fabrication of “prototype”

24. 24 Processing of two flat cut on barrel surface ARD-OPTICS Ltd (Armenia), Partner of IMPEX (Germany) E-mail from Dr. Ruben Babasyan (3 Feb. 2015) “We are polishing the second face.” Dummy bulk (Shinkosha) 3. Fabrication of “prototype” (1)Sapphire lop-eared suspension 205 mm 164 mm in thickness

25. 25 Processing of two flat cut on barrel surface ARD-OPTICS Ltd (Armenia) The first surface ! 3. Fabrication of “prototype” (1)Sapphire lop-eared suspension

26. 26 Two ears ARD-OPTICS Ltd (Armenia), Partner of IMPEX (Germany) Photo from Armenia 3. Fabrication of “prototype” (1)Sapphire lop-eared suspension

27. 27 Four sapphire fibers with nail heads : IMPEX E-mail from Dr. Lena Barsukowa (29 Jan. 2015) “The processing of fiber is progressing according to plan till now.” 3. Fabrication of “prototype” (1)Sapphire lop-eared suspension

28. 28 Four blade spring : Shinkosha (Japan) They have already delivered three pieces and two more pieces will come by the end of March. Sapphire blade spring 3. Fabrication of “prototype” (1)Sapphire lop-eared suspension

29. 29 Dummy mirror and ears (stainless) Mechanical Engineering Center of KEK has already delivered ! 220 mm 150 mm 3. Fabrication of “prototype” (2)Cryo-payload with dummy sapphire suspension

30. 30 Intermediate mass We ordered VIC (http://www.vic-int.co.jp/)http://www.vic-int.co.jp/ and the parts will come by the end of March. Recoil mass Processing in Mechanical Engineering Center of KEK is in progress. Mirror 3. Fabrication of “prototype” (2)Cryo-payload with dummy sapphire suspension

31. 31 Three topics from young researchers (1)Sapphire suspension thermal noise : Dan Chen (2) Sapphire blade spring : Hiroki Tanaka (3) Sensors and motors to adjust tilt angle : Takahiro Miyamoto 4. R&D items

32. 32 (1)Sapphire suspension thermal noise D. Chen measured mechanical loss of fiber and bonding. Moreover, he derived thermal noise from his measured result using ANSYS. 4. R&D items

33. 33 (2)Sapphire blade spring 33 4. R&D items Fiber length difference compensation Design : R. Kumar et al., GWADW2014 (http://www.gravity.ircs.titech.ac.jp/GWADW2014/slide/Rahul_ Kumar.pdf) Shinkosha made such blade springs ! Resonant frequency of vertical mode Measurement : 14.3 Hz, Calculation : 14.4 Hz Hiroki Tanaka investigated long term (one month) drift with load.

34. Motor and sensor to adjust angle of mass of payload is necessary. At least, they must work at cryogenic temperautre and in vacuum. Takahiro Miyamoto is investigating what kinds of sensor and motors are able to work at cryogenic temperature. 34 (3)Sensors and motors to adjust tilt angle 34 4. R&D items

35. 35 (3)Sensors and motors to adjust tilt angle 35 Above black cubic corresponds to a small red box. A screw goes through this cubic. The motor rotates this screw and the black cubic moves along the screw. 4. R&D items When a small red box was moved by a motor, the center of PF or IM is also moved. Since PF and IM are suspended by a fiber, their angle is changed. D. Chen

36. 36 (1)Sapphire suspension thermal noise(Chen)

37. 37 (1)Sapphire suspension thermal noise(Chen)

38. 38 (1)Sapphire suspension thermal noise(Chen)

39. 39 (1)Sapphire suspension thermal noise(Chen)

40. 40 (1)Sapphire suspension thermal noise(Chen)

41. 41 (1)Sapphire suspension thermal noise(Chen)

42. 42 (2)Sapphire blade spring (Tanaka)

43. 43 (2)Sapphire blade spring (Tanaka)

44. 44 (3)Sensors and motors to adjust tilt angle (Miyamoto) Purpose The motors and sensors to adjust the angle of masses of cryogenic payload are inevitable for operation of detector. They should work at cryogenic temperature(and in vacuum). I am performing operation examinations for candidates of motors and sensors at cryogenic temperature (in vacuum).

45. 45 Motor test (Miyamoto) Stepping motor (ORIENT MOTOR MODEL PK525A) State of the test(~20K) Al Mass ~100g I tested the motor which is no compatible with low temperature (and vacuums). Therefor, I removed oil used inside the motor. The movement of the mass can be observed. Direction of motion

46. Sensor test (Miyamamoto) Since our motor can move the mass at cryogenic temperature. We will use it for the sensor cryogenic test. We will check whether the sensor can monitor the motion of Al mass by motor. I am preparing test of Light reflection displacement sensor. Light from LED is reflected by target and goes to photodiode(PD). The light intensity depend on D. Thus we can derive D from output of PD. D

47. 47 ELiTES: ET-LCGT interferometric Telescope Exchange of Scientists Grant for collaboration about cryogenic between KAGRA and ET. Ettore Majorana reports in this afternoon. Kazuhiro Yamamoto will report on the next Monday (9th of Feb) in 3rd ELiTES meeting. ELiTES

48. 48 5. Summary Two kinds of full size prototypes (1)Sapphire lop-eared suspension (2)Cryo-payload with dummy sapphire suspension Design and fabrication of prototypes (1)Sapphire lop-eared suspension : All sapphire parts will be delivered by the end of March. (2)Cryo-payload with dummy sapphire suspension Dummy mass, recoil mass, intermediate mass were or will be delivered by the end of March. However, still many parts must be designed.

49. 49 5. Summary R&D items (1)Sapphire suspension thermal noise : Dan Chen measured mechanical loss of fiber and bonding. Evaluated thermal noise is enough small. (2)Sapphire blade spring : Hiroki Tanaka observed the displacement with load in one month. This spring survived ! (3)Sensors and motors to adjust tilt angle Takahiro Miyamoto confirmed a motor (ORIENT MOTOR MODEL PK525A) works at cryogenic temperature. He adopts this motor to check how cooled light reflection displacement sensor works.

50. 50 Thank you for your attention !

51. 51 Cryogenic payload Dummy mirror and ears (stainless) 3. Payload S. Koike

52. 52 Cryogenic payload Dummy mirror and ears (stainless) 3. Payload S. Koike

53. 53 Cryogenic payload Dummy mirror and ears (stainless) 3. Payload S. Koike

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61. 61 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 S. Koike 1. Introduction

62. 62 2 Pulse tube cryocoolers Pulse tube cryocoolers Baffles Cryo duct(Yusuke’s talk) Outer shield (80K) Inner shield (8K) Vacuum chamber (300K) 1. Introduction

63. 63 Hole on radiation shield for wire from SAS. Duct to reduce radiation invasion is necessary. 63 2. Cryostat Baffles Cryo duct(Yusuke’s talk)

64. 64 CuBe blade spring in platform Intermediate Mass Intermediate Recoil Mass Test Mass (sapphire mirror) Platform includes CuBe spring for vertical vibration isolation. 3. Payload

65. 65 CuBe blade spring in platform Large CuBe blade spring (provided by VIS group) in 1/4 cryostat in ICRR. They will be moved to KEK on the 8th of Aug. 3. Payload

66. 66 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

67. 67 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

68. 68 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 …