About ICRR
Chronology
Showa 251950Asahi Hut (wooden structure; about 50 sq. meters) was constructed on Mt. Norikura based on the Asahi Bounty for Science.
Showa 281953Asahi Hut was incorporated into the Cosmic Ray Observatory, the University of Tokyo (Aug. 1).
Showa 301955The main building and research facilities of the Norikura Observatory were constructed (the opening ceremony was held on Aug. 29).
Showa 311956-- The Cosmic Ray Division (composed of Air Shower Section and Emulsion Section) was inaugurated at the Institute for Nuclear Study, the University of Tokyo.
Showa 321957The Norikura Observatory participated in IGY (International Geophysical Year) activities, and began air shower observation.
Showa 331958The emulsion chambers at Norikura Observatory started operation.
Showa 341959-- Air shower observation started at the Institute for Nuclear Study, the University of Tokyo.
Showa 351960-- The Emulsion Section of the Institute for Nuclear Study, the University of Tokyo, developed a large-size balloon.
-- International projects of the Japan Society for the Promotion of Science started (international collaboration with India, Brazil and Bolivia).
Showa 411966-- The balloon project of Emulsion group of Institute for Nuclear Study, the University of Tokyo, was transferred to the Institute of Space and Aeronautical Science, the University of Tokyo.
Showa 431968-- The Emulsion Section of the Institute for Nuclear Study, the University of Tokyo, started observation on Mt. Fuji with emulsion chambers.
Showa 471972A full-time director was appointed.
The construction of MUTRON was commenced.
-- The cosmic material research section was established in the Cosmic Ray Division of the Institute for Nuclear Study.
Showa 481973The ultra-high energy weak-interation division was newly established.
The international projects of the Japan Society for the Promotion of Science (with India, Brazil and Bolivia) were incorporated.
Showa 491974A full-time chief administrator was appointed.
Showa 501975MUTRON was completed.
The construction of the Akeno Observatory started.
The ultra-high energy strong-interaction division was newly established.
Showa 511976In the wake of the amendment of the National School Establishment Law, the observatory was reorganized into the Institute for Cosmic Ray Research (ICRR) (25 Aug); The ultra-high energy strong-interation division was divided into two divisions, and the three divisions of the Institute for Nuclear Study, the University of Tokyo (muon measurement, experimental meson physics and cosmic ray study) were transferred to ICRR. As the result, ICRR started out with 6 divisions and 1 observatory.
Showa 521977The Akeno observatory was established as one of the ICRR facilities (18 Apr).
Showa 531978The Akeno Observatory performed the opening ceremony (6 Oct).
Showa 541979The Akeno 1km2 air shower detector was completed.
The special facility for emulsion chamber on Mt. Fuji was constructed.
The 16th International Cosmic Ray Conference was held in Kyoto (Aug).
Showa 561981Japan-China joint research on emulsion chamber observations started.
Showa 571982The cosmic ray detection division (for guest researchers) was newly established.
Showa 581983The nucleon decay experiment started in the Kamioka Mine as a collaborative research project.
The primary cosmic ray research facility (i.e. mass spectrometer etc.) was installed.
Showa 611986The first committee for future projects was organized.
Showa 621987The underground detector at Kamioka observed a neutrino burst from a supernova for the first time in history.
The construction of the 100km2 wide-area air shower detector, AGASA, started at the Akeno Observatory.
The first committee for future project submitted an evaluation report.
Showa 631988The underground detector at Kamioka observed a deficit in solar neutrino flux.
Heisei 011989A significant increase of cosmic ray intensity coincident with a solar flare was observed at the Norikura Observatory (29 Sep).
Heisei 021990

The 100km2 wide area air shower detector, AGASA, was completed at Akeno.

Heisei 031991The construction of Super-Kamiokande was commenced.
The second committee for future projects was organized.
Heisei 041992The neutrino astrophysics division was newly established, and the cosmic ray detection division (for guest researchers) was discontinued.
The gravitational wave group joined in muon measurement division at ICRR.
The Cangaroo project started in Australia
The Cangaroo observed TeV gamma rays from a pulsar (PSR1706-44).
Heisei 051993The construction of air shower gamma ray detector in Tibet started.
Heisei 061994A computer center was built at Kamioka Observatory (Jan).
The excavation for SuperKamiokande was completed (Jun).
A giant air shower with energy of 2×1020 eV was observed at Akeno
An external evaluation of ICRR was conducted.
The anormalous zenith angle dependence of the atmospheric neutrinos was observed at Kamioka.
Heisei 071995The neutrino astrophysics division was discontinued, and the Kamioka Observatory for Cosmic Elementary Particle Research was established (1 Apr)
The completion ceremony of Super-Kamiokande was held before filling water (Nov).
Heisei 081996The full-scale operation of Super-Kamiokande began (1 Apr).
Heisei 091997The air shower gamma ray detector in Tibet was completed.
Heisei 101998The Super-Kamiokande collaboration officially announced the discovery of none-zero neutrino mass (5 Jun).
The construction of the Kashiwa Campus was commenced (Nov).
Heisei 111999The Research Center for Cosmic Neutrinos was established (1 Apr).
The Cangaroo-2 began operation in Australia.
Preparation of the Cangaroo-3 began in Australia.
Heisei 12 2000ICRR moved to the new Kashiwa Campus (Feb.-Mar.).
Heisei 13 2001An accident occurred at the Super-Kamiokande, destroying more than half of the photomultipliers (Nov.).
Heisei 14 2002Professor Emeritus Masatoshi Koshiba won the Novel Prize in Physics for his pioneering contributions to the detection of cosmic neutrinos, based on outcomes of the Kamiokande experiment (Dec.).
The Super-Kamiokande was partially restored, and observation resumed (Dec.).
Heisei 15 2003The 28th International Cosmic Ray Conference was held in Tsukuba (Aug.).
The construction of the Telescope Array was commenced.
Four telescopes for the Cangaroo-3 Project were completed.
Heisei 16 2004 Japanese national universities became independent administrative agencies (Apr.1).
The research divisions of ICRR were reorganized into the three divisions: Neutrino and Astroparticle Division, High Energy Cosmic Ray Division, and Astrophysics and Gravity Division (Apr.1).
Heisei 18 2006 The restoration of the Super-Kamiokande was completed.
Heisei 19 2007 The Committee on Future Projects III was established.
The Committee on Future Projects III submitted its report.
Heisei 20 2008 The Telescope Array experiment started observation.
Heisei 22 2010

The Super-Kamiokande detected the first neutrino from the T2K experiment.
ICRR became an Inter-University Research Center, renewing its existing function as an inter-university research institute.
The Large Cryogenic Gravitational Wave Telescope (LCGT) was approved as a Leading-edge Research Infrastructure Program. The construction started.

Heisei 23 2011 The Gravitational Wave Project Office was established (Apr. 1).
The T2K experiment caught a sign of electron neutrino appearance (Jun. 15).
The Committee on Future Projects IV was established.
Heisei 24 2012 The Cangaroo experiment ended its operation.
Heisei 26 2014 The excavation of KAGRA tunnel was completed (Jul.).