LCGT
Encyclopedia
The Large Scale Cryogenic Gravitational Wave Telescope (LCGT) is a future project of the gravitational wave
studies group at the Institute for Cosmic Ray Research
(ICRR) of the University of Tokyo
. The ICRR was established in 1976 for cosmic ray studies, and is currently working on TAMA 300
. The LCGT project was approved on 22 June 2010.
The current plan is for two sets of 3 km (1.9 mi) arm length laser interferometric
gravitational wave detector
s to be built in a tunnel of Kamioka mine in Japan
. LCGT will detect chirp waves from binary neutron star coalescence at 240 Mpc away with a S/N
of 10. The expected number of detectable events in a year is two or three. To achieve the required sensitivity, several advanced techniques will be employed such as a low-frequency vibration-isolation system, a suspension point interferometer, cryogenic mirrors, a resonant side band extraction method, a high-power laser
system and so on. LCGT was initially expected to be operational in 2009 but is now likely to enter operation in 2018
Gravitational wave
In physics, gravitational waves are theoretical ripples in the curvature of spacetime which propagates as a wave, traveling outward from the source. Predicted to exist by Albert Einstein in 1916 on the basis of his theory of general relativity, gravitational waves theoretically transport energy as...
studies group at the Institute for Cosmic Ray Research
Institute for Cosmic Ray Research
The Institute for Cosmic Ray Research of the University of Tokyo was established in 1976 for the study of cosmic rays....
(ICRR) of the University of Tokyo
University of Tokyo
, abbreviated as , is a major research university located in Tokyo, Japan. The University has 10 faculties with a total of around 30,000 students, 2,100 of whom are foreign. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most prestigious university...
. The ICRR was established in 1976 for cosmic ray studies, and is currently working on TAMA 300
TAMA 300
TAMA 300 is a gravitational wave detector located at the Mitaka campus of the National Astronomical Observatory of Japan. It is a project of the gravitational wave studies group at the Institute for Cosmic Ray Research of the University of Tokyo...
. The LCGT project was approved on 22 June 2010.
The current plan is for two sets of 3 km (1.9 mi) arm length laser interferometric
Interferometry
Interferometry refers to a family of techniques in which electromagnetic waves are superimposed in order to extract information about the waves. An instrument used to interfere waves is called an interferometer. Interferometry is an important investigative technique in the fields of astronomy,...
gravitational wave detector
Gravitational wave detector
A gravitational wave detector is any experiment designed to measure gravitational waves, minute distortions of spacetime that are predicted by Einstein's theory of general relativity. The existence of gravitational radiation is a prediction of Einstein's general theory of relativity. Gravitational...
s to be built in a tunnel of Kamioka mine in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. LCGT will detect chirp waves from binary neutron star coalescence at 240 Mpc away with a S/N
Signal-to-noise ratio
Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise...
of 10. The expected number of detectable events in a year is two or three. To achieve the required sensitivity, several advanced techniques will be employed such as a low-frequency vibration-isolation system, a suspension point interferometer, cryogenic mirrors, a resonant side band extraction method, a high-power laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
system and so on. LCGT was initially expected to be operational in 2009 but is now likely to enter operation in 2018