抄録
Liquid mercury target system for high power spallation neutron sources is being developed. When high intensity proton beams are injected into the target, pressure waves are generated by thermal shock in mercury and cavitation damage will be imposed on the target vessel. Injection of micro bubbles into mercury is effective to mitigate the pressure waves. In this work, we propose a method of fabricating a micro nozzle for the bubbles injection purpose. The method is based on powder metallurgy by inserting thin glass fibers into a metal powder matrix to create a green compact, followed by sintering at a temperature between the melting points of the powder and fiber. SUS316L and molybdenum powders were used as the nozzle matrix material. The sintered metal had straight holes with circular cross-section, in which the diameter and the aspect ratio are approximately 100μm and 200, respectively.
