ABSTRACT
RESULTS AND DISCUSSION The relative intensities of the lines emitted by the species in the discharge can be used to obtain certain parameters characteristic of the plasma state, among them the so-called excitation temperature, T. If the departure atomic levels corresponding to this transitions are at least in Local Thermodynamic Equilibrium (LTE), the method of the Boltzmann-plot can be used to determine this temperature [4]. If the excited atomic states fulfil a Boltzmann-type balance among them by means of collisional processes with free electrons, then T„, can equal electron temperature, T. When the plasma is not in the referential equilibrium state denominated LTE, we can define, for each excited atomic level p, the parameter of departure from equilibrium as:
(P) (1)
where p is the effective principal quantum number of the level, n(p) the actual density of the excited level and ns(p) the density corresponding to the Saha equilibrium. When the levels are overpopulated, b(p) > 1 and the term "ionising plasma" is used. If the distribution function of free electrons is Maxwellian, it can be seen that [5].
