Progress on the cryogenic system for the interferometric cryogenic gravitational wave telescope, KAGRA

Document #:

JGW-G1301726-v2

Document type:

G

Submitted by:

Nobuhiro Kimura

Updated by:

Nobuhiro Kimura

Document Created:

09 Jul 2013, 23:43

Contents Revised:

10 Jul 2013, 01:08

DB Info Revised:

10 Jul 2013, 01:08

Abstract:

Japanese large-scale cryogenic gravitational wave telescope, KAGRA, aims to detect gravitational waves using an interferometer having 3 km in length of arms. The notable feature of KAGRA is four main mirrors of the interferometer are cooled down below 20 K in order to reduce thermal noise. With the design of the cryogenic system for KAGRA, a cryo-payload consisting of the mirror and its suspension system is connected with two very-low-vibration cryo-cooler units as cooling devices, and is surrounded by the radiation shield (2.5m^3 in volume) below 20K in a cryostat.
Each cooling device consists of a pulse-tube type cryocooler (0.9W at 4K), a specifically designed mechanical frame and the conduction cooling links made of 6N class high purity aluminum.
Fabrication of four cryostats and sixteen very-low-vibration cryocooler units was started at 2011, and completed on the end of March 2013. All of the cryocooler units confirmed their expected cooling performance, as 2.5 W at 9 K, and the overall vibration characteristic less than 10^-7 m/ Hz^0.5 at the connection edge of conductive cooling passage. KAGRA collaborators carried out total performance tests including cooling characteristic with a half size of dummy cryo-payload and measurements of vibration of the radiation shield.
Detail of thermal and mechanical design of the cryogenic system for KAGRA and its performance was reported in the conference.

Files in Document:

• Presented at Amardi 10 (Amaldi10-talk-C3-130709.ppt, 5.7 MB)

Topics:

• Management:Conference
• Activity:KAGRA
• Detector:Cryogenic

Authors:

• Nobuhiro Kimura

Keywords:

Cryogenics Cryostat Cryocooler

Notes and Changes:

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