J-PARC stands for Japan Proton Accelerator Research Complex, a state-of-the-art accelerator research facility in Japan. J-PARC is a joint project of the Japan Atomic Energy Agency (JAEA) and the High Energy Accelerator Research Organization (KEK).
  The research conducted at J-PARC's experimental facilities covers a wide range. For example, some scientists explore material and life science through atomic-scale observations. Others study elementary particles and atomic nuclei to unravel the mysteries of the dawn of the universe. Here at J-PARC, a world-class, high-intensity beam of protons is accelerated to nearly the speed of light. The various secondary particle beams, neutrons, muons, neutrinos, kaons, etc., are produced in nucleus spallation with the proton beam. These secondary particle beams are used in a wide variety of experiments.
  J-PARC welcomes many researchers not only from Japan but also from overseas to its three accelerator facilities such as Linac, RCS of the 3 GeV synchrotron, MR of the main ring, and three experimental facilities such as the Materials and Life Science Experimental Facility, Neutrino Experimental Facility, and Hadron Experimental Facility, as well as for research related to the nuclear transmutation technology under construction. Scientists then work with collaborators to advance diverse research and development activities, from basic science to industrial applications.


2001 April    JAEA and KEK signed a cooperative agreement on the construction, research, and development of J-PARC.
December    Construction of J-PARC facilities started.
2005 August    JAEA and KEK signed a cooperative agreement on the management of J-PARC.
2006 February    J-PARC center was established.
2007 January    Expected energy was achieved at Linac.
October    Expected energy was achieved at RCS.
2008 May    First beam was successfully received for neutron target at MLF.
September    First beam was successfully received for muon target at MLF.
December    Initial target energy (30 GeV) was achieved at MR.
December    Utilization of the Materials and Life Sciences Facility (MLF) was started.
2009 January    Hadron Experimental Facility was completed.
March    Neutrino Experimental Facility was completed.
July    Neutron Beam Facility of J-PARC was designated as a facility subject to Public Utilization Promotion Act.
November    First neutrino was successfully observed by the T2K near neutrino detector.
December    The world's highest intensity of muon generation per pulse was confirmed at MLF.
2011 March    Operation was suspended due to the Great East Japan Earthquake.
2012 January    Operation resumed and user operation started.
November    The world's highest intensity of neutron generation per pulse was confirmed at MLF.
2013 May     Incident at the Hadron Experimental Facility occurred.
2014 January    Energy upgrade was achieved at Linac.
2015 January    Short pulse 1 MW was achieved at MLF.
April    User operation resumed at Hadron Experimental Facility.
2018 July    Continuous operation with a beam power equivalent to 1 MW was succeeded at MLF.
2019 September    J-PARC 10th Anniversary Ceremony and J-PARC Symposium 2019 were held.
2020 April    Operation and user operation were suspended due to COVID-19.
June    36.5 hours of 1 MW user operation was implemented.
February    Hyper-Kamiokande Project started.
2021 June    Samples from asteroid Ryugu were analyzed at J-PARC.
2022 March    International users resumed experimentation for the first time in two years after the coronavirus disaster.