What is KAGRA?

KAGRA is a gravitational wave detector located in the Kamioka Observatory in Gifu Prefecture, Japan. Its full name is the Kamioka Gravitational Wave Detector, and it is the first such detector in the world to be built underground. KAGRA is designed to detect gravitational waves, ripples in space-time caused by the violent movements of massive objects such as black holes and neutron stars.

History of KAGRA project

The KAGRA project started in 2008 and was led by the Institute for Cosmic Ray Research (ICRR) at the University of Tokyo. The construction of the detector began in 2010, and it was completed in 2019. The project was partly funded by the Japanese government and received support from international partners, including the United States and Europe. KAGRA is part of a global network of gravitational wave detectors that includes the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States and the Virgo detector in Italy.

Key features of KAGRA

KAGRA’s unique feature is its underground location. The detector is housed in a tunnel excavated 200 meters underground to minimize the effects of seismic noise and other disturbances from the Earth’s surface. The detector itself consists of four 3-kilometer-long arms arranged in an L-shape, which are used to detect gravitational waves. The arms are made of ultra-high vacuum chambers that contain mirrors that reflect laser beams. When a gravitational wave passes through KAGRA, it causes tiny changes in the length of the arms, which are detected by the laser beams.

Examples of KAGRA’s scientific contributions

KAGRA has already made significant contributions to the field of gravitational wave astronomy. In February 2020, it detected its first gravitational wave signal, which was caused by the collision of two black holes 7 billion light-years away. This detection was the first made by a gravitational wave detector located in Asia. KAGRA also works in conjunction with other detectors to pinpoint the origin of gravitational waves, which can help to identify the objects that caused them. KAGRA’s underground location also makes it an ideal detector for detecting low-frequency gravitational waves, which are difficult to detect using other detectors. Overall, KAGRA is an important addition to the global network of gravitational wave detectors and is expected to contribute to many more exciting discoveries in the future.