Innovative Helium-Cooled Tungsten PFCs

70732 Helium has been found to be an attractive coolant for fusion power plants based on its safety advantages and compatibility with structural materials at high temperature. However, gas coolants in general tend to provide modest heat transfer performance due to their inherently low heat capacity and heat transfer coefficient. This project will use near net shape fabrication techniques and a novel placement of the helium supply artery to develop helium-cooled tungsten plasma facing components in high heat flux regions. In Phase I, a refractory metal porous medium with high porosity content (10-30% dense) and elongated pores will be developed to minimize pressure drops and improve heat transfer. The braze joints for the helium supply and return ducts will be eliminated to minimize potential failures in high heat flux regions. Tungsten brush armor will be evaluated to protect the heat sink from thermal erosion and off-normal events. In addition, cost effective fabrication techniques will be developed to produce alloyed and dispersion-strengthened refractory metal components, which will result in improved ductility and increased creep resistance. Commercial Applications and Other Benefits as described by the awardee: Possible applications include heat pipes, sputtering targets for electronics manufacture, X-ray targets for medical devices, industrial mold armor, high temperature protective coatings, rocket engines, valve surfacing, pump protection, combustors, chemical processing equipment, nose cones, power generation systems, furnace components, etc.