Fusion product bombardment of a tokamak first wall

Publisher Website
Google Scholar
Abstract
A method of calculating the wall loading due to fusion products escaping from the plasma in a tokamak is described. For this purpose, the small-banana-width approximation is eliminated, yielding an analytic formulation for high-energy orbits and associated loss-cone limits. Wall-loading profiles (as a function of poloidal angle) are presented for various experimental devices (PLT, TFTR, and ORNL-EPR) and for a typical reactor (UWMAK-I). Peak-to-average alpha flux ratios of the order of 1.4 to 2.3 combined with average fluxes of ~ 1011 alphas per cm2 per second, suggest that localized blistering may be a serious source of impurity atoms as well as a wall erosion mechanism. Special wall panels in regions of high flux are suggested. Other implications include a unique suggestion for fuel injection along special orbits intercepted via a bundle divertor.