A radial particle-in-cell model of the weakly-collisional plasma discharge in a Hall thruster, provides the non-Maxwellian velocity distribution functions (VDF) of ions and electrons. The model considers a radial magnetic field, secondary electron emission from the two walls, and phenomenological models of anomalous electron scattering. The electron VDF is used to assess the different terms in the macroscopic momentum and energy equations, identifying those differing from the standard fluid model for a near-Maxwellian VDF. The pressure tensor consists of an anisotropic gyrotropic part and a small gyroviscous part. Nonetheless, the gradient of this last one affects the cross-field electron current density, generating radial undulations that resemble those reported for near-wall conductivity. A gyroviscous energy flux is identified too. The heat flux parallel to the magnetic lines does not follow a conductive-type law but a convective-type one, already found in other weakly-collisional plasmas. The tails of the electron velocity distribution function are partially depleted due to wall collection, leading to reduced electron fluxes of particles and energy, which are characterized with parameters useful for fluid models. Differences in the plasma response for annular and planar channel geometries are highlighted. The levels of replenishment of the electron VDF and of the asymmetries in radial profiles differ for isotropic and anisotropic anomalous scattering models.

A 1D Particle-In-Cell model of a Hall thruster discharge is used to analyze the effect of a curved magnetic topology in the radial plasma response and the plasma fluxes to dielectric walls. The kinetic solution shows a significant replenishment of the velocity distribution function tail and temperature isotropization for both negative (i.e. anode pointing) and positive curvatures. The new radial magnetic force is electron confining or expanding for, respectively, negative and positive curvatures, and this modifies significantly the electric and pressure radial forces. As a consequence, the plasma density near the wall and the degree of radial ion defocusing are affected: they are highly reduced for negative curvatures, the case of higher interest. For positive curvatures, the kinetic solution shows that the radial ion flow becomes supersonic within the plasma bulk, away from the Debye sheaths. An ancillary quasineutral fluid model is presented to explain this feature and other aspects of the kinetic solution. Some kinetic studies on additional phenomena complete the work.