Development of rotating-disk target for J-PARC Hadron Beamline

We have developed a new production target with a beam power up to 150 kW or more for the Hadron Experimental Facility at J-PARC. A primary candidate of the new target is a rotating disk in which platinum or gold is bonded on a periphery of a nickel disk edge. As for a cooling method of the disk, helium-gas cooling is better than water cooling from the viewpoint of controls of corrosion and radioactive materials. However, cooling efficiency for the rotating disks by helium gas, that is 'heat-transfer coefficient', is lower than that by the water cooling, and very difficult to theoretically estimate. Therefore, we have constructed a test bench to measure the heat-transfer coefficient of the rotating disk, and established an estimation method. In this report, the basic design of the new production target and the estimation of the heat-transfer coefficient in a simple setup are presented. (author)