Nitrogen Gas Laser Filament Plasma Kinetic System Stability Analysis under Parameter Variation

Author(s): Ofer Aluf Netanya

A nitrogen laser is a gas laser operating in the ultraviolet range (typically 337.1 nm) using molecular nitrogen as its gain medium, pumped by an electrical discharge. It is efficient sources for laserinduced fluorescence and photochemistry and general spectroscopy. There is a model for a singlepass, discharge type standoff nitrogen laser initiated by a femtosecond filament in nitrogen gas. A Nitrogen gas laser filament plasma kinetic system is described by the set of plasma kinetic equations which associated with rate equations for the population of the lasing levels and number of emitted photons. The change of concentration of different neural and ionic atomic and molecular species in the filament plasma is described by set of rate equation, Ns is the density of species of type - s, and Gs, Ls are the relevant generation and loss rates. T, Te, and Tvibr are gas, electronic, and vibrational temperatures, respectively. The concentration of system gas is not balanced and Te≈ Tvibr. T parameters transform to T→TE+Ω?√T; TE?N, Ω ?R. We discuss the system stability and stability switching for different values of TE and Ω parameter. There is a practical guideline that combines graphical information with analytical work to effectively study the local stability of models involving dependent parameters. The stability of a given steady state is determined by the graphs of some function of TE and Ω parameters.