[en] The Japan Proton Accelerator Research Complex (J-PARC) is now under construction at Tokai site of Japan Atomic Energy Research Institute. The main parts of J-PARC are composed of 400 MeV linear accelerator, 3 GeV booster and 50 GeV proton synchrotron accelerators (50 GeV-PS). The beam energy is 30 GeV in the first phase operation mainly due to the budget limitation. We obtained beam envelopes and momentum dispersions on the matching space, switchyard and Nuclear Atom Element Particle Experimental Hall (NP-Hall). Total beam length is 260 m. The beam emittance are 4.4π in horizontal and 10.4π in vertical mm mr. There are four focusing point in the beam line for beam control, beam branching, additional beam line and test target. The beam size in the target position 0.8 mm (root mean square) in horizontal and 1.4 mm (root mean square) in vertical. The Construction group is examining the proposed secondary beam lines. A typical example of NP-Hall lay out including the secondary beam lines is shown. Beam envelopes and dispersion are obtained for the secondary beam lines (K1.8), which supply Max 2 GeV K meson. Lay out of Additional beam line (K1.1BR, K1.1 and HR) are discussed. Specifications of the secondary beam lines are summarized in a table. Further optimization will be continued in relation with physics requirements. (Y. Tanaka)

[en] In order to verify presence of neutrino oscillation at present, the K2K experiment is carried out. The K2K is an abbreviation of 'KEK to Kamiokande', where KEK is a place forming neutrino and Kamiokande is an elementary particle observation apparatus with 40 m in diameter, 42 m in height, and 50,000 ton of pure water, and situated at 1,000 m in depth of the old Kamioka mine in Gifu prefecture. For formation of neutrino, proton beam by 12 GeV accelerator at KEK was used. The proton beam passed through 400 m of neutrino beam line, and was charged into a target in a horn situated at it downstream to form particle and pi meson constituting origin of neutrino formation. The pulse source was flown 250 kA of pulse current into a horn electromagnet synchronously with taking out of proton beam from an accelerator (two seconds in period) in order to focus pi meson to a direction of the Kamiokande. Here were reported on design to operation results on the apparatus comprising of capacitor, high voltage capacitor, thyristor switch, and pulse transformer. (G.K.)