Particle-in-cell simulations of the plasma-wall transition with a magnetic field almost parallel to the wall

Using simple analyses and 1d3v (one space and three velocity dimension) particle-in-cell simulations we show that the properties of the plasma-wall transition change when the angle α between the wall and the magnetic field is of the order of, or smaller than, certain values α1, α2. These values depend on the ion mass and collisionality, and on the ion-to-electron temperature ratio in the magnetic presheath. In this range of α, no significant decrease in the particle and heat fluxes to the wall is expected with decreasing α.