Simulating the effect of poloidal particle source on the bootstrap current and benchmarking to analytic estimates in tokamak edge pedestal

Abstract

The bootstrap current profile in the tokamak pedestal is studied numerically using the plasma code ELMFIRE in neoclassical simulations with Joint European Torus-like parameters. The effect of a poloidally localized atom source on the bootstrap current is investigated while assuming that the ionization takes place in the pedestal region. A clear effect of poloidal source location is found within one poloidal Larmor radius for thermal particles. For cold particles, this poloidal dependence largely disappears. Without source, the simulated bootstrap current is compared to two different analytical estimates and their accuracy is tested in terms of gradient scale lengths and collisionality.