Investigation of the Concentration Dynamics of H2O and HDO Molecules in a Discharge

The results of a joint measurement of the concentration of H 2 O and HDO molecules in a glow discharge in a quartz tube by the modified method of diode laser spectroscopy with an external resonator are presented. The off-axis radiation input mode makes it possible to determine the parameters of absorption lines at low pressure. The H 2 O/HDO isotopic ratio in the discharge is measured for different compositions of a plasma-forming mixture. The dynamics of the concentration of water molecules during inlet without discharge is studied and the role of interaction of these molecules with the walls of the facility in the formation of the plasma composition is discussed.