Dynamics of the water molecule density in a discharge chamber filled with a low-pressure humid gas

The dynamics of the H₂O molecule density in a metal gas-discharge chamber filled with low-pressure water vapor or its mixtures with noble gases was investigated by manometric and spectral methods. Regimes both with and without discharge excitation were studied. In the absence of a discharge, the molecule density dynamics is governed by the heterogeneous interaction of molecules with the chamber walls. In the presence of a discharge, in addition to the heterogeneous interaction, fast plasmachemical molecule dissociation also contributes to the initial stage of H₂O molecule loss. The role of heating of the chamber walls is discussed.