Speaker
Takayuki Tomaru
(National Astronomical Observatory of Japan)
Description
KAGRA is an only gravitational wave telescope using cryogenic mirror system. Although cryogenic sapphire mirror and suspension is the most direct way to reduce thermal noises, a technical issue is to cope with both cooling and vibration isolation. We worked on this issue for 20 years and realized in KAGRA now. For example, special technologies in KAGRA cooling system are followings;
- Ultra-small vibration cryocooler system
- Funneling effect in beam tubes and its reduction by black coating
- Ultra-soft and large thermal-conductive heat-link
- Heat-link vibration isolation system
- Ultra-small out-gas thermal insulator
And recently, we found an issue of mirror frosting by adsorption of residual gas in cryostat by cryogenic pump effect, and studies this phenomena and solution.
In this presentation, cooling system of KAGRA and some of the issues will be reported.
Primary author
Takayuki Tomaru
(National Astronomical Observatory of Japan)
