Waad Wouter Graef

Global (volume-averaged) model of inductively coupled chlorine plasma : influence of Cl wall recombination and external heating on continuous and pulse-modulated plasmas

An inductively coupled radio-frequency plasma in chlorine is investigated via a global (volume-averaged) model, both in continuous and square wave modulated power input modes. After the power is switched off (in a pulsed mode) an ion–ion plasma appears. In order to model this phenomenon, a novel quasi-neutrality implementation is proposed. Several distinct Cl wall recombination probability measurements exist in the literature, and their effect on the simulation data is compared. We also investigated the effect of the gas temperature that was imposed over the range 300–1500 K, not calculated self-consistently. Comparison with published experimental data from several sources for both continuous and pulsed modes shows good agreement with the simulation results.

High repetition rate laser induced fluorescence applied to Surfatron Induced Plasmas

The reaction kinetics in the excitation space of Ar and the conversion space of Ar-molecule mixtures are explored using a combination of high rep-rate YAG-Dye laser systems with a well defined and easily controllable Surfatron Induced Plasma set-up. Applying the method of Saturation Time Resolved Laser Induced Fluorescence (SaTiRe-LIF), we could trace excitation and conversion channels and determine rates of electron and heavy particle excitation kinetics. The time resolved density disturbances observed in the Ar excitation space, which are initiated by the laser, reveal the excitation channels and corresponding rates; responses of the molecular radiation in Ar-molecule mixtures corresponds to the presence of conversion processes induced by heavy particle excitation kinetics.

Simplifying plasma chemistry via ILDM

A plasma fluid model containing a large number of chemical species and reactions yields a high computational load. One of the methods to overcome this difficulty is to apply Chemical Reduction Techniques as used in combustion engineering. The chemical reduction technique that we study here is ILDM (Intrinsic Lower Dimensional Manifold). The ILDM method is used to simplify an argon plasma model and then a comparison is made with a CRM (Collisional Radiative Model).