Magnesium as a representative analyte metal in argon inductively coupled plasmas. II. Population mechanisms in analytical zones of different spectrochemical systems

The extensive collisional-radiative model is applied to the actual argon inductively coupled plasmas (ICP) in order to clarify consistently the mechanisms by which the excited levels of magnesium atoms and ions are populated in analytical zones of these ICP systems. Computations are carried out for various sets of input parameters, such as the electron temperature the Te, atom temperature Ta, the electron number density ne and the optical escape factors Amn and Am for Mg atoms, and Amn+ and Am+ for Mg+ ions. The predicted values of the populations in the excited levels and the quantities derived from them are fairly close to the corresponding experimental results. The effect of the changes in the discharge parameters Te, Ta, ne, A1n, and A1n+ on the population mechanisms, together with the role played by the upward excitation flows of electrons from the respective ground states and by the charge transfer between argon and magnesium, are also shown.