A two-dimensional fluid model for a dusty argon plasma in which the plasma and dust parameters are solved self-consistently, is used to study the behavior of voids, i.e., dust-free regions inside dust clouds. These voids appear in plasma crystal experiments performed under microgravity conditions. The ion drag force turns out to be the most promising driving force behind these voids. The contribution of the thermophoretic force, driven by the temperature gradient induced by gas heating from ion-neutral collisions, can be neglected in the quasineutral center of the plasma.

A two-dimensional hydrodynamic model for a dusty argon plasma in which the plasma and dust parameters are solved self-consistently has been supplemented with a separate dust particle tracing module to study the behavior of dust vortices. These coherent vortices appear in plasma crystal experiments performed under microgravity conditions. The nonconservative total force exerted by the discharge on the dust particles is responsible for the generation of the vortices. The contribution of the thermophoretic force driven by the gas temperature gradient plays an insignificant role in the generation of the vortices, even when the gas heating via the dust particles is taken into account. The forces related to the electric field, including the ion drag force, are dominant.

A dusty radio-frequency silane/hydrogen discharge is simulated, with the use of a one-dimensional fluid model. In the model, discharge quantities like the fluxes, densities, and electric field are calculated self consistently. A radius and an initial density profile for the spherical dust particles are given and the charge and the density of the dust are calculated with an iterative method. During the transport of the dust, its charge is kept constant in time. The dust influences the electric field distribution through its charge and the density of the plasma through recombination of positive ions and electrons at its surface. In the model this process gives an extra production of silane radicals, since the growth of dust is not included. Results are presented for situations in which the dust significantly changes the discharge characteristics, both by a strong reduction of the electron density and by altering the electric field by its charge. Simulations for dust with a radius of 2 μm show that the stationary solution of the dust density and the average electric field depend on the total amount of the dust. The presence of dust enhances the deposition rate of amorphous silicon at the electrodes because of the rise in the average electron energy associated with the decrease of the electron density and the constraint of a constant power input.

In this paper hydrodynamic and kinetic approaches to model low pressure capacitively coupled radio-frequency discharges are discussed. In particular approaches and results for power modulated discharges in a mixture of silane and hydrogen and for discharges containing a considerable amount of dust particles will be presented.

A dusty radio-frequency argon discharge is simulated with the use of a two-dimensional fluid model. In the model, discharge quantities, such as the fluxes, densities, and electric field are calculated self-consistently. The charge and density of the dust are calculated with an iterative method. During the transport of the dust, its charge is kept constant in time. The dust influences the electric potential distribution through its charge and the density of the plasma through recombination of positive ions and electrons on its surface. Results are presented for situations in which the dust significantly changes the discharge characteristics, both by a strong reduction of the electron density and by altering the electric potential by its charge. Simulations for dust particles having a radius of 7.5 microm show that a double space charge layer is created around the sharp boundary of the dust crystal. A central dust-free region (void) is created by the ion drag force. Inside this void a strong increase of the production of argon metastables is found. This phenomenon is in agreement with experimental observations, where an enhanced light emission is seen inside the void.