Fast gas heating and kinetics of electronically excited states in a nanosecond capillary discharge in CO₂

Fast gas heating in a pulsed nanosecond capillary discharge in pure CO2 under the conditions of high specific deposited energy (around 1.2 eV/molecule) and high reduced electric fields (150-250 Td) has been studied experimentally and numerically. Specific deposited energy, reduced electric field and gas temperature have been measured as functions of time. The radial distribution of the electron density has been analyzed experimentally. The role of quenching of O(1D), O(1S) and CO(a3Π) excited atoms and molecules leading to heat release at sub-microsecond time scale have been analyzed by numerical modeling in the framework of 1D axial approximation.