LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Status of the Cryogenics Design N. KIMURA A, S. KOIKE B, T. KUME B, T. OHMORI D, Y. SAITO C, Y. SAKAKIBARA E, K. SASAKI A, Y. SATO C, T. SUZUKI A, T. UCHIYAMA E, K. YAMAMOTO E, H. YAMAOKA C and LCGT Collaboration A Cryogenics Science Center/KEK B Mechanical Engineering Center/KEK C Accelerator Laboratory/KEK D Teikyo University E Institute for Cosmic Ray Research University of Tokyo/ICRR

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA 2 Outline Required Issues for the Cryogenics Cryostat design Components Response to ground motion Thermal Budget Preliminary performance of the cryo-cooler unit with anti-vibration stage Summary

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Temperature of the test mass/mirror < 20 K. Inner radiation shield have to be cooled < 8 K. The mirror have to be cooled without introducing excess noise, especially vibration from the cryo-coolers. Accessibility and enough volume for the installation work around the mirror. Satisfy ultra high vacuum specification < Pa. Required Issuess for the Cryogenics Design

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Main beam (1200mm FL) to SAS View ports Remote valve Low vibration cryocooler unit Main LASER beam  2.4m ~3.8m Cryostat Stainless steel t20mm Diameter 2.4m Height ~3.8m M ~ 10 ton Cryocoolers Pulse tube, 60Hz 0.9 W at 4K (2nd) 36 W at 50K (1st) Drawn by S. Koike (KEK) Cryostat accompany with the four cryocooler units Components of Mirror Cryostat

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA The interior of the cryostat Double radiation shields with hinged doors Support rods View Ports Heat path to cryocooler Drawn by S. Koike (KEK)

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Static deformation analysis Main vacuum duct and the duct to SAS are not connected. periphery of the bottom : fix S.Koike

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Modal analysis of outer shield Mass= Mode frequency Mass= S.Koike Remove support rod Mode Frequency

Cryo-top Cryo-L Cryo-F Input Cryo-R X-directionY-direction X 方向 Y 方向 Analyzing of Response to ground motion resonant frequency

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA 9 Estimated Thermal Budget Estimated Heat Loads at the radiation shields and Support posts and rods 70 W by the radiation at 80 K outer shield 2.2 W by the radiation at 8 K inner shield 24 W by the radiation and conduction (support posts and tension rods) at 80 K 2.4 W by the radiation and conduction (support posts and tension rods) at 8 K Low Vibration Cryo-cooler unit Very High Purity Aluminum Conductor (5N8) Connection point with IM dT 2nd =0.5 K 94 K at the top of the 80 K outer shield 7.4 K at the top of the 8 K inner shield 47 K at 1 st cold stage of Cryo-cooler 6.5 K at 2nd cold stage of Cryo- cooler dT 1st = 26 K

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA 10 Estimated Heat load Outer Shield (W) ◦ Eleven View Ports 22 ◦ Radiation From 300 K 70 ◦ Support post and Rods 24 ◦ Electrical wires 3 x Total 116 W/unit 29 Inner Shield (W) ◦ Duct Shields* < 0.05 (Beam and SAS) ◦ Eleven View Ports 0.4 ◦ Radiation From 80 K 2.2 ◦ Support post and Rods 2.4 ◦ Electrical wires 3 x ◦ Mirror Deposition 0.9 ◦ Scattering Light ? Total5.9 W/unit1.5 *Heat Load of Duct Shields will be presented by Mr. Sakakibara. 1 st Cold stage2 nd Cold stage

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Proto-type cryocooler unit under the performance test Tri-axial Laser Displacement meter Vacuum duct for very high pure aluminum thermal conductor Plus tube type cryo-cooler with anti-vibration stage

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Cooling curve of proto-type cryo-cooler unit with visualization windows for displace measurements Internal heaters on 2 nd stage=0.9 W 1 st stage=30.0 W Reached lowest temp. 2 nd stage=8 K 1 st stage=35 K Results; Cooling down to 8 K with 25 kg2.1 days “ to 80 K with 45 kg 1.5 days Estimated Cooling Speed; Cooling down to 8 K with 410 kg9 days “ to 80 K with 880 kg 11 days

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Vibration Level at edge of AL thermal conductor Vertical PTC connection Axial Horizontal L=2 m

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA F.F.T. analysis (Ex. Axial direction) Axial Results of displacement at connection point Axial < 200 nm Horizontal < 50 nm Vertical < 10 nm

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Summary 15 The design of the mirror cryostat for LCGT, which was satisfied required issues was finished. The production of the components for the cryostat will start after contractor decided. Performance of the first cryostat will be demonstrated on the mid of 2012 Jfy. Performance of the first cryo-cooler will be confirmed on the mid of this August.

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Back UP

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA F.F.T. analysis (Vertical direction) Vertical

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA F.F.T. analysis (Horizontal direction) Horizontal

LCGT f2f meeting/ICRR, 04/Aug./2011 N. KIMURA Production plan of LCGT mirror cryostats and peripheral components Manufacture components Assemble and factory test with cryo-coolers Transport to Kamioka Custody at Kamioka 2011 Jfy2012 Jfy2013 Jfy ‘12.3‘13.3‘14.3‘11.3 Design by KEK ‘ We are here Four Mirror Cryostats Cryo-cooler units Design by KEK Proto-type Cryo-cooler unit test Production of 7 cryo- cooler units Production of 9 cryo- cooler units Transport to Kamioka Custody at Kamioka Performance test Duct shield units Design by KEK Production of Proto-type ducts shield units with cryo-coolers Performance test