Kinetics of electron states of hydrogen molecules in nonequilibrium discharges: Singlet states

International audienceThis study continues previous publications devoted to kinetic processes in nonequilibrium hydrogen plasma. This review contains an analysis of the kinetics of hydrogen molecules in the ground state and in excited singlet electron states in various gas discharges. The distribution functions measured over the vibrational levels of a hydrogen molecule in the ground electron state are compared with those calculated within the developed level semiempirical collisional-radiative model of low-temperature hydrogen plasma. A database of the measured and calculated collisional-radiative characteristics of kinetic processes involving excited hydrogen molecules and the parameters of low-temperature hydrogen plasma is formed

Plasma processes controlled by the adjustment of particle and energy fluxes

International audienceAn electronic state sensitive semiempirical collision-radiative model of hydrogen plasma of ECR-discharge is used to analyze the applicability of emission of triplet states of molecular hydrogen for plasma diagnostics. It is shown that secondary processes make the greatest contribution to the kinetics of population-depopulation of triplet states ${a}^{3}{{\rm{\Sigma }}}_{g}^{+},{c}^{3}{{\rm{\Pi }}}_{u},{d}^{3}{{\rm{\Pi }}}_{u},{e}^{3}{{\rm{\Sigma }}}_{u}^{+},{g}^{3}{{\rm{\Sigma }}}_{g}^{+},{h}^{3}{{\rm{\Sigma }}}_{g}^{+}$, i 3Πg and r 3Πg. The secondary processes give the smallest contribution to the excitation and deactivation of triplet states {f}^{3}{{\rm{\Sigma }}}_{u}^{+}\,{\unicode{x00438;}}\,{k}^{3}{{\rm{\Pi }}}_{u}. Thus a simplified coronal model (electron impact excitation followed by radiative decay) can be used to process the intensities of the dipole allowed ${f}^{3}{{\rm{\Sigma }}}_{u}^{+}\,\to \,{a}^{3}{{\rm{\Sigma }}}_{g}^{+},{g}^{3}{{\rm{\Sigma }}}_{g}^{+}$ and ${k}^{3}{{\rm{\Pi }}}_{u}\,\to \,{a}^{3}{{\rm{\Sigma }}}_{g}^{+}$ transitions. The complicated collision-radiative model should be used for other transitions

Plasma assisted Pulsed Laser Deposition for the improvement of thin film growth

In this paper, results are reported on the characterization of thin films of titanium dioxide and chalcogenide glass doped with praseodymium by the technique of plasma-assisted pulsed laser deposition (PA-PLD) with biased substrate. This technique is shown to be able to prevent contamination of deposited films by particles ejected and to improve the pulsed laser deposition process for stoichiometry, morphology and optical properties of the films produced

Study of the rovibrational levels of ground state excited hydrogen molecules by laser photodetachment and emission spectroscopy

Proc. num. Clé USBInternational audienc

Study of the rovibrational levels of ground state excited hydrogen molecules by laser photodetachment and emission spectroscopy

Proc. num. Clé USBInternational audienc