Quest for Direct Detection of Gravitational Waves and Large-scale Cryogenic Gravitational wave Telescope (LCGT) Project in Japan

Abstract

  The quest of direct detection of gravitational waves (GWs) has reached the most interesting stage. During GW observation using LIGO and partially VIRGO and GEO600 for three years, no GW events were observed within a ∼15 Mpc radius from the Earth. To detect several GW events per year, enhancement of strain sensitivity, about ten times as high as for these GW detectors, is in progress. In Japan, Large-scale Cryogenic Gravitational wave Telescope (LCGT) project has also started in 2010 to detect GWs and to form a GW detection network with other GW detectors. LCGT will be constructed at the Kamioka mine, Hida-city, Gifu-prefecture. It is located about 200 meters under the ground surface for stable operation. LCGT is also designed to utilize cryogenic mirrors and cryogenic mirror suspension wires to reduce thermal noises and to reach the quantum noise limiting sensitivity of 10⁻²² in rms strain.