The influence of nitrogen entrainment on argon plasmas created by the 'Torche a Injection Axiale' (TIA)

When a plasma is sustained in the open air, nitrogen will diffuse into the plasma. Especially for plasmas sustained by the 'Torche a Injection Axiale' (TIA) this appears to be the ease, since this turbulent jet draws gases fr om the surroundings. In the argon plasma the entrained nitrogen is probably converted into N-2(+) (via charge transfer with argon ions), which is cons equently destroyed by dissociative recombination (DR). This mechanism affec ts the plasma in two ways: (1) it offers an important loss channel for the free electrons and (2) the gas is heated by the kinetic energy of the nitro gen atoms produced in the DR reaction.