AN INVESTIGATION OF THE BALANCE OF CHARGE-EXCHANGE BETWEEN MG AND AR IONS IN THE ICP

Pulsed dye lasers were used to manipulate the excited state populations of magnesium atoms and ions to examine the importance of charge exchange as an excitation and ionization mechanism in the inductively coupled plasma (ICP). Laser enhanced ionization of ground-state magnesium resulted in a decrease in emission from Mg II 4s2S and 3d2D levels, indicating that charge transfer is the predominant mechanism for the population of those levels. Double-resonant laser excitation of ground state magnesium ions to the Mg II 4s2S level resulted in an increase in the emission from the Mg I 285.213 nm resonance line, demonstrating the importance of the reverse reaction.