Abstract: Evaporization rate of impurity elements was determined in the presence of different fluorat-ing agents. Arc temperature, electron pressure, ionization degree of impurity elements were calculated. On the basis of these data, all kinds of factors influencing the element spectral intensity are discussed. Reaction products in the electrode cavity were analysed with X-ray diffraction. Under these conditions the mechanism of the fluorination reaction is proposed, and demonstrated by thermodynami-cal calculation.

Key words: Direct current arc discharge, Controlled atmosphere, Fluorination reaction