Correlation spectroscopy as a probe of excitation and ionization mechanisms in the inductively coupled plasma

Correlations between intensity fluctuations in atomic and ionic emission lines were used as indicators of ionization and excitation mechanisms in the inductively coupled plasma. Ionic lines excited by charge exchange were positively correlated with neutral atom emission, while those excited by electron impact showed a negative correlation. An analog correlator was constructed to allow rapid measurement of such correlations over a broad range of wavelengths and as a function of position in the plasma. Results obtained to date suggest that charge exchange contributes significantly to the excitation and ionization of Mg, Y, Ti and V in the inductively coupled plasma.