Glow discharge optical emission spectrometry : GD-OES

Principle

A Glow Discharge Optical Emission Spectrometer (GD-OES) comprises a glow discharge source and one or more optical spectrometers. Fig.1 shows the schematic diagram of measuring principle. In a glow discharge, cathodic sputtering is used to remove materials layer by layer from the sample surface. The sputtered atoms are excited once in the process of collisions with electrons or metastable carrier gases, followed relaxation into a stable state again. Then, the emission during the process is observed and the characteristic spectrum is precisely analyzed. Continuous measurement enables to obtain depth profiles of composed elements.