A remote handling magnet system in a branch region of a new primary beam line at the J-PARC Hadron Facility (2)

A new primary proton beam line, which is called high-p/COMET beam line (B-line), is now under construction at the J-PARC Hadron Facility. B-line is branched off from the existing primary proton beam line (A-line) in the middle of the beam-switching yard. We use a Lambertson magnet and two septum magnets as the splitting devices for the B-line. At the Lambertson magnet, there is field-off hole in the yoke of the magnet. Almost amount of the beam goes through the hole and is transported to the A-line. And very tiny fraction of the beam is kicked off at 5 degree and is transported to the B-line at the same time. At the edge of the field-off hole, there is a significant beam-loss. Therefore, those magnets work in high radioactive environment. Those magnets are placed on the plug-in base assembled with water and electric-power quick disconnect devices. The installation of those magnets is completed in 2018, and the first beam introduced to the A-line. Next year the first beam will be introduced to the high-p experimental area. (author)