Characteristics of the collisional dissociation of N2F4 excited by resonant infrared radiation

An investigation was made of the collisional dissociation of tetrafluorohydrazine N₂F₄ + M → 2NF₂ + M initiated by CO₂ laser radiation. It was found that at low excitation levels (~1 photon/molecule) the process is in thermodynamic equilibrium, and its kinetics is governed by the condition for adiabatic dissociation. An increase in the energy input to ~3 photons/molecule gives rise to a radiative dissociation stage which is independent of pressure. This is followed by nonequilibrium collisional dissociation involving additional activation with a radiative molecular energy distribution function. The experimental results were used to obtain estimates for the characteristic times of collisionless (~40 nsec) and collisional decay (~0.2 μsec·Torr) of the excited level and also to estimate the vibrational–translational relaxation time of N₂F₄ (5 <τ_VT <20 μsec·Torr).