Experimental and theoretical modeling of runaway electron damage for the design of tokamak plasma facing components

Summary Form only given, as follows. Damage of tokamak components and materials due to high-energy runaway electrons (20-150 MeV) during disruptions is being investigated. A computational model of the effect of the runaway electrons is being used to predict the energy deposition and damage on tokamak first wall and limiter materials. The results from this model will be used to design components that can withstand high energy runaway electron damage. To date, parametric studies of electron energy, incident angle, current, and deposition time have been performed to determine their effect on energy deposition and temperature rise in various materials (including graphite, zirconium, molybdenum, tungsten, beryllium). The conclusion is that an optimum material would have a high melting temperature, high thermal conductivity, and the capability to scatter high-energy electrons into a large volume. The temperature rises predicted by the model agreed favorably with experimental temperature rises. In addition to modeling damage due to melting and sublimation, investigation of other damage mechanisms is underway.<>