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arXiv · 0704.2881

Current status of Japanese detectors

Daisuke Tatsumi·Ryutaro Takahashi·Koji Arai·Noriyasu Nakagawa·Kazuhiro Agatsuma·Toshitaka Yamazaki·Mitsuhiro Fukushima·Masa-Katsu Fujimoto·Akiteru Takamori·Alessandro Bertolini·Virginio Sannibale·Riccardo DeSalvo·Szabolcs Marka·Masaki Ando·Kimio Tsubono·Tomomi Akutsu·Kazuhiro Yamamoto·Hideki Ishitsuka·Takashi Uchiyama·Shinji Miyoki·Masatake Ohashi·Kazuaki Kuroda·Norichika Awaya·Nobuyuki Kanda·Akito Araya·Souichi Telada·Takayuki Tomaru·Tomiyoshi Haruyama·Akira Yamamoto·Nobuaki Sato·Toshitaka Suzuki·Takakazu Shintomi
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Abstract

Current status of TAMA and CLIO detectors in Japan is reported in this article. These two interferometric gravitational-wave detectors are being developed for the large cryogenic gravitational wave telescope (LCGT) which is a future plan for detecting gravitational wave signals at least once per year. TAMA300 is being upgraded to improve the sensitivity in low frequency region after the last observation experiment in 2004. To reduce the seismic noises, we are installing new seismic isolation system, which is called TAMA Seismic Attenuation System, for the four test masses. We confirmed stable mass locks of a cavity and improvements of length and angular fluctuations by using two SASs. We are currently optimizing the performance of the third and fourth SASs. We continue TAMA300 operation and R&D studies for LCGT. Next data taking in the summer of 2007 is planned. CLIO is a 100-m baseline length prototype detector for LCGT to investigate interferometer performance in cryogenic condition. The key features of CLIO are that it locates Kamioka underground site for low seismic noise level, and adopts cryogenic Sapphire mirrors for low thermal noise level. The first operation of the cryogenic interferometer was successfully demonstrated in February of 2006. Current sensitivity at room temperature is close to the target sensitivity within a factor of 4. Several observation experiments at room temperature have been done. Once the displacement noise reaches at thermal noise level of room temperature, its improvement by cooling test mass mirrors should be demonstrated.

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Daisuke Tatsumi, Ryutaro Takahashi, Koji Arai, Noriyasu Nakagawa, Kazuhiro Agatsuma, Toshitaka Yamazaki, Mitsuhiro Fukushima, Masa-Katsu Fujimoto, Akiteru Takamori, Alessandro Bertolini, Virginio Sannibale, Riccardo DeSalvo, Szabolcs Marka, Masaki Ando, Kimio Tsubono, Tomomi Akutsu, Kazuhiro Yamamoto, Hideki Ishitsuka, Takashi Uchiyama, Shinji Miyoki, Masatake Ohashi, Kazuaki Kuroda, Norichika Awaya, Nobuyuki Kanda, Akito Araya, Souichi Telada, Takayuki Tomaru, Tomiyoshi Haruyama, Akira Yamamoto, Nobuaki Sato, Toshitaka Suzuki, Takakazu Shintomi. 2007-04-22. Current status of Japanese detectors. https://doi.org/10.1088/0264-9381%2F24%2F19%2Fs03

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