Performance of the INTOR poloidal divertor

The next generation of large tokamak experiments is expected to have large particle and heat outfluxes (approx.1023 particles/s and 80 MW). These outfluxes must be controlled to provide adequate pumping of the helium ''ash'' and to minimize the sputtering erosion of the vacuum vessel walls, limiters, and neutralizer plates. A poloidal divertor design to solve these problems for INTOR has been done using a two-dimensional code which models the plasma as a fluid and solves equations for the flow of particles, momentum and energy, and calculates the neutral gas transport with Monte-Carlo techniques. These calculations show that there is a regime of operation where the density in the divertor is high and the temperature is low, thus easing the heat load and erosion problems. The neutral pressure at the plate is high, resulting in high gas throughputs with modest pumping speeds