The difference between the electron temperature and the gas temperature in a stationary arc plasma at atmospheric pressure

Deals with an experimental and theoretical study of the difference between the electron temperature T e and the gas temperature T g in a stationary cylindrical argon plasma. The experimental method is based on the measurement of a line coefficient, during the first microseconds of plasma decay, which presents a jump due to the equalisation of temperatures. A theoretical model with rate equations and the electron energy balance has been developed. The comparison between experimental and theoretical values of the difference (T e -T g ) has been carried out for several current intensities and radial positions. The agreement is good for an arc with a 6 mm diameter. For a 4 mm diameter the computed values are less precise than the experimental ones because of the inaccuracy of diffusion terms which play an important part in the computation of (T e -T g ).