Characterization of Atomic Emission Lines from Argon, Neon, and Nitrogen Glow Discharge Plasmas

Emission lines and the relative intensities of Cu, Ag, Sn, Al, and Zn are investigated In the wavelength range from 200 to 600 nm when excited with a Griimm-type glow discharge light source. Argon, neon, or nitrogen gas is introduced Into the discharge tube to create a glow discharge plasma. The spectrum patterns strongly depend on the kind of foreign gas rather than the other discharge conditions such as the gas pressure and the discharge voltage. Especially, the emission Intensities from the singly ionized species are drastically changed by choosing various foreign gases even if the other conditions are kept constant. These observations suggest that the energy levels and their excitation energies of each foreign gas play significant roles for determining the ionization and excitation of the analyte atoms.