Ana Samolov

Characterization of the supersonic flowing microwave discharge using two dimensional plasma tomography

A tomographic numerical method based on the two-dimensional Radon formula for a cylindrical cavity has been employed for obtaining spatial distributions of the argon excited levels. The spectroscopy measurements were taken at different positions and directions to observe populations of excited species in the plasmoid region and the corresponding excitation temperatures. Excited argon states are concentrated near the tube walls, thus, confirming the assumption that the post discharge plasma is dominantly sustained by travelling surface wave. An automated optical measurement system has been developed for reconstruction of local plasma parameters of the plasmoid structure formed in an argon supersonic flowing microwave discharge. The system carries out angle and distance measurements using a rotating, flat mirror, as well as two high precision stepper motors operated by a microcontroller-based system and several sensors for precise feedback control.

Tomographic analysis of plasma sources with distorted cylindrical symmetry

The tomographic reconstruction of local plasma parameters for nonequilibrium plasma sources is an indispensable tool for understanding the fundamental processes and phenomena that follow the dynamics of plasmas with complex geometry. We present practical approaches that are developed on the case-to-case basis and applied to several plasma sources in our laboratories.

Data evaluation and fitting of electron impact ionization cross sections of Ar, Cl, F, N2, O2, Cl2, F2 and their ions for plasma modeling

The still growing influence of the plasma technologies on the worlds largest manufacturing industries, puts new requirements on the quality of atomic data supplied. Maybe more than ever the field of plasma modeling is in need of reliable electron impact ionization cross sections data. This work aims to provide accurate analytical fits for the most common atomic species found in plasmas, such as Argon and halogen elements like Fluorine and Chlorine, etc. The first attempts for the analytical fitting of the relevant molecular species are also made. The standard BELI formula is revisited, however other analytical expressions are suggested, too, for approximating single-ionization cross sections. In the evaluation process the preference is given to experimental data up to date covering the whole range in energies. The question of the factors effecting the accuracy of the fits is addressed as well.