Abstract
The construction of the J-PARC facility [1] was started in 2001 as a joint venture between KEK (High Energy Accelerator Research Organization) and JAERI (Japan Atomic Energy Research Institute, which was reorganized as JAEA (Japan Atomic Energy Agency) in 2005). The J-PARC facility is composed of a 400 MeV linac [2], a 3 GeV rapid cycling synchrotron (RCS) [3], and a 50 GeV synchrotron (MR, the beam energy is at present 30 GeV) [4], a materials and life science experimental facility, a hadron experimental facility, and a neutrino experimental facility as shown in Figure 1. The neutrino facility sends a neutrino beam to Super KAMIOKANDE. The beam commissioning to the beam lines planned at the first step had been successfully achieved as shown in Figure 2.