Ionization of Na(3P) atoms by collisions with vibrationally excited nitrogen molecules in crossed molecular beams

A crossed molecular beam experiment is described in which the rate of ionization of Na(3P) atoms in collision with vibrationally excited N₂ molecul has been measured as a function of the N₂ temperature up to 3050 K. The activation energy in the experiment appears to be close to the ionization energy of the 3P level. An ionization cross section of about 100 »A² (excluding the activation energy factor) is derived with the help of a theoretical model. The limitations of the experiments as well as of the model are discussed.