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The Kamioka Gravitational Wave Detector (KAGRA), formerly 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. In January 2012, it was given its new name, KAGRA, deriving the "KA" from its location at the Kamioka mine and "GRA" from gravity and gravitational radiation.[1]

KAGRA has two sets of 3 km (1.9 mi) arm length laser interferometric gravitational wave detectors which were being built in tunnels of Kamioka mine in Japan. The excavation phase of tunnels was completed on 31 March 2014. KAGRA 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. KAGRA was initially hoped to begin operations in 2009[2] but is now likely to enter operation in 2018.[3]


  1. ^ "LCGT got new nickname "KAGRA"". 
  2. ^ Uchiyama, T. et al. (2004). "Present status of large-scale cryogenic gravitational wave telescope". Class. Quantum Grav. 21 (5): S1161–S1172. Bibcode:2004CQGra..21S1161U. doi:10.1088/0264-9381/21/5/115. , free version available at "Present status of large-scale cryogenic gravitational wave telescope" (PDF). 
  3. ^ Kuroda, K et al. (April 2010). "Status of LCGT". Class. Quantum Grav. 27 (8): 084004. Bibcode:2010CQGra..27h4004K. doi:10.1088/0264-9381/27/8/084004. , free version available at "Status of LCGT" (PDF).