[en] Inactivating viable cells at very short application times has been studied using Ultra Low Frequency Plasma (ULFP) at one Kilo Hertz, using an RF source. The targeted fashion is to inactivate Escherichia coli (E. coli) in the absence and in the presence of magnetic field. Adding oxygen (O₂₎ to argon (Ar) in the discharge leads to a complete bacterial inactivation, where the inactivation rate increased as the concentration of O₂ increases. Analyses of the experimental data of the initial and final densities of viable cells, using survival curves, showed a dramatic inhibitory effect of plasma discharge to the residual survival of microbial ratio due to the influence of the magnetic field.

[en] Cylindrical probe data have been analyzed using different theories in order to determine some plasma parameters (electron temperature and electron and ion densities). Langmuir probe data are obtained in a cylindrical DC glow discharge in the positive column plasma at argon gas pressures varied from 0.5 to 6 Torr and at constant discharge current equal to 10 mA. The electron density has calculated from the electron current at the space potential and from Orbital Motion Limited (OML) collisionless theory. Ion density has obtained from the OML analysis of the ion saturation currents. In addition, the electron temperature has measured by three different methods using probe and electrons currents. The electron temperature T_e, plasma density n_e, and space potential V_s, have been obtained from the measured single cylindrical probe I–V characteristic curves. The radial distribution of the electron temperature and plasma density along the glow discharge are measured and discussed. Using the collisionless theories by Langmuir cylindrical probe and up to several Torr argon gas pressures the differences between the values of electron temperature and electron and ion densities stay within reasonable error limits.