Fluid model of the boundary of a one-dimensional plasma under the influence of an oblique magnetic field for a wide range of collisionality

The effect of a magnetic field on the boundary of a plasma is studied using a one-dimensional fluid model based on the work of K.-U. Riemann [Contrib. Plasma. Phys. 34, 127 (1994)]. The model takes into account the effects of both collisions and ionization. Two limiting regimes are identified: the collisional presheath and the (highly) magnetized presheath. Results from this model demonstrate that a highly magnetized presheath may be treated in terms of two regions: The B-aligned presheath and a Chodura layer [R. Chodura, Phys. Fluids 25, 1628 (1982)]. The properties of this Chodura layer are explored in some detail and it is found that the size of this layer, for example, follows a simple expression in the highly magnetized regime. Finally, an attempt is made to recover the singular behavior of the Chodura layer as the magnetic field becomes very strong and use a pseudo two-scale approach to resolve both scale lengths of the magnetized presheath.