J-PARC Neutrino Experimental Facility has been built to carry out forefront neutrino research using the world's highest intensity neutrino beam. The facility was designed and realized by the High Energy Accelerator Research Organization (KEK) with a major contribution from the T2K international collaboration. The construction of the facility began in 2004 and was completed in March, 2009. The data collection in the T2K experiment commenced in January 2010 (See below).
What is neutrino ? Neutrino is one of the most basic building blocks of universe - elementary particles -, which has a very tiny mass compared to other elementary particles, and are thought to be three types - flavors -. Because a neutrino penetrates almost everything (e.g., rocks) with very little interactions, it is very difficult to be detected. (Visit introduction to the T2K experiment in more detail.)
Tokai to Kamioka (T2K) is a Japanese-led multinational physics experiment designed to unveil mysteries of the elusive particle, neutrino. High-intensity neutrino beams are directed from the J-PARC neutrino facility at Tokai in Ibaraki Prefecture towards Super-Kamiokande-the world's largest underground neutrino detector-located in Hida, Gifu Prefecture, 295km away.