Observatory and Facility

Kashiwa Campus
Research Center for
Cosmic Neutrinos

Kamioka Observatory

Institute for
Cosmic Ray Research
Kashiwa-City,
Chiba-Prefecture

Kamioka, Hida-City,
Gifu-Prefecture

KAGRA Observatory

High Energy Astrophysics
Facility in Canarias

Kamioka, Hida-City,
Gifu-Prefecture

La Palma,
Canary Islands, Spain

Norikura Observatory

The University of Tokyo

Akeno Observatory

Institute for Cosmic Ray Research (ICRR)The University of Tokyo
Nyukawa-cho,Takayama-City,
Gifu-Prefecture

Akeno-cho, Hokuto-City,
Yamanashi-Prefecture

We have a lotof original
goods for sale!

5-1-5 Kashiwanoha, Kashiwa-City, Chiba-Prefecture 277-8582 Japan

URL : https://www.icrr.u-tokyo.ac.jp

ICRR aims to solve the problem of the Universeand particle physics through the observation ofhigh-energy charged particles (cosmic rays),gamma rays, neutrinos, gravitational waves,etc. from the outer space.

What is Cosmic Ray?
“Cosmic rays” are particles that travel from the Universe to theEarth with high energy. Since their discovery in 1912, various
research has been carried out with the aim of elucidating theirorigins and acceleration mechanisms. In the initial cosmic rayresearch, “cosmic rays” were charged particles such as protons
and helium nuclei, but in recent years, uncharged elementary
particles such as neutrinos, gamma rays and gravitational waves(gravitons) are also considered to be “cosmic rays,” broadening
the scope of cosmic ray research. Since cosmic rays travel overlong distances, larger than the size of the Earth, and areaccelerated to extremely high energies, they facilitate research on
elementary particles that cannot be conducted in accelerator
experiments on the ground. ICRR conducts fundamental researchon the Universe and elementary particles using cosmic rays.

Experimental Facilities

High Energy Cosmic Ray ResearchHigh Energy Astrophysics Group

Cherenkov Telescope Array Group
This group aims to explore the extreme Universe
with the next-generation very-high-energy
gamma-ray observatory CTA, which has higher
detection sensitivity and broader energy coverageby order of magnitude than current telescopes.
The discovery of thousands of gamma-rayobjects, suchas black holes
and neutronstars, isexpected.

This group theoretically studies high-energy astrophysical phenomena, such asformation of relativistic jets, particle
acceleration, and emission mechanisms,with electromagnetic radiations, cosmicrays, neutrinos and gravitational waves.

We have many Large-scale Equipments.
Tibet ASγ/ ALPACA Experiment Group
This group deploys air shower detectors studying ultrahigh energy cosmic gamma rays and very high energy
cosmic rays both at Tibet heights, China (altitude:4300m) and at heights near Mt. Chacaltaya, Bolivia(altitude:4740m) to find out origin of cosmic rays
around 1015eV energies and how they are accelerated.

ALPACA Experiment in Bolivia

Telescope Array Group
This group aims to find out where the extremely
high energy cosmic rays; around 1020eV come from.

Neutrino and Astroparticle Research

History of ICRR
The history of ICRR began with a cosmic ray observation hut called
Asahi Hut on Mt. Norikura at an altitude of 2,770m. This small hut,built in 1950 with science project funding from the Asahi Shimbun,
developed into the Cosmic Ray Observatory (commonly called
Norikura Observatory) of The University of Tokyo in 1953. It was
the first inter-university research facility in Japan. The Cosmic RayObservatory was then reorganized to become the Institute for
Cosmic Ray Research (ICRR) of The University of Tokyo in 1976.
Since then, ICRR has carried out various research activities oncosmic rays as an inter-university research institute.

Organization of ICRRICRR has three research divisions—the Neutrino and Astroparticle
division, the High Energy Cosmic Ray division, and theAstrophysics and Gravity division—in order to conduct thesescientific activities effectively. ICRR has four observatories inJapan; Kamioka Observatory (underground in Kamioka, Gifu
Prefecture), KAGRA Observatory (underground in Kamioka, GifuPrefecture), Norikura Observatory (2,770 meters alt., Mt. Norikura,Gifu Prefecture) and Akeno Observatory (Yamanashi Prefecture),and one research center (Research Center for Cosmic Neutrinos,Kashiwa, Chiba Prefecture). In addition, there are four observation
facilities outside Japan, located in Utah, USA, Yangbajing in Tibet,China, High Energy Astrophysics Facility in Canarias (La Palma,Spain), and Chacaltaya, Bolivia. ICRR is an “International Joint
Research/Usage Center,” which is a system of the Japanese
government, and over 150 inter-university research programs havebeen carried out at ICRR by cosmic ray researchers in Japan andother countries.

Super-Kamiokande Group
Hyper-Kamiokande GroupLa Palma,
Canary Islands,
SpainUtah, USA

Astrophysics and Gravity Research
Theory Group
This group works on solving theoreticalproblems of Cosmology and Particle
Phenomenology.
Research topics are to reveal
mysteries of the early Universein Cosmology, and searching themore fundamental law of nature
in Particle Phenomenology. Bothtopics focus on the extremely early
history, about one second from thebeginning of the Universe.
Observational Cosmology Group
This group aims to explore the earlyUniverse by deep multi-wavelength
observations with the state-of-the-art
telescopes such as Subaru Telescope,
ALMA,and James Webb Space
Telescope. Research purpose is tounderstand physical processes ofgalaxy formation at
the early stage andthe relevant event ofcosmic reionization.

Kamioka,
Hida-City,
Gifu-Prefecture
Tibet, China

Atacama,
ChileMt. Chacaltaya,
Bolivia

Gravitational Wave Group

This group aims to promote
gravitational wave astronomy byparticipating the global gravitational
wave observation network with thelarge- scale cryogenic gravitational
wave telescope, KAGRA.

Construction Scene ofHyper-Kamiokande

Dark Matter
Direct Detection Group

What are the material constituents ofthe Universe? This is one of the mostfundamental questions, and we knowthat most of them are NOT atoms ormolecules but something called darkmatter. This group aims at detecting
dark matter particles directly.

Super-Kamiodane(SK) and Hyper-Kamiokande(HK) groups aim to reveal
the history of the Universe and explore
the nature of elementary particles
through the observation of neutrinos
and the discovery of proton decay.SK
is upgrading to SK-Gd with increasedsensitivity for anti-electron neutrinos
starting in 2020. HK, with about ten
times the effective volume of SK, will
start its operation in 2027.

T2K Experiment GroupT2K is a neutrino experiment
designed to study how neutrinoschange as they travel (neutrinooscillations) with an intense
muon-neutrino beam generated
at J-PARC and the Super-Kamiokande as a far detector.