Fusion-product transport in axisymmetric Tokamaks: Losses and thermalization

Prompt escape loss fluxes were calculated including the nonseparable dependence of flux as a function of poloidal angle and local angle of incidence at the first wall. The flux was strongly peaked at near grazing incidence, suggesting that blistering injected impurities can reduce reactor burn times by 50-70%. Nonprompt losses were also calculated and make a small contribution to impurity production. Sensitivity studies show the plasma wall separation to be the strongest factor controlling prompt losses. Modest increases in wall radius (plasma radius fixed) of a device, such as the ORNL-EPR, were found to reduce blistering injected impurities to a level which should no longer limit the burn time. Fusion product (p) thermalization and heating was calculated assuming classical slowing down. An analytical model is presented that describes fast ion orbits and their distribution function to realistic high beta, noncircular Tokamak equilibria.