Guiding centre simulation of the bootstrap current in a plasma with a current hole

摘要

The bootstrap current in a tokamak plasma with a very small poloidal magnetic field near the magnetic axis (current hole) is computed with guiding centre particle simulations including a Monte Carlo model of pitch-angle scattering. We find that the bootstrap current is very small inside the current hole, while the parallel plasma flow is of similar size as the neoclassical flow due to the pressure gradient outside the current hole.