Analytical Sciences

Abstract − Analytical Sciences, 26(3), 303 (2010).

Emission Spectroscopic Study on Gas–Gas Interactions in Glow Discharge Plasmas Using Several Binary Gas Mixtures
Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
Emission spectra of constituent gas species from glow discharge plasmas using argon–helium, krypton–helium, argon–krypton, and krypton–argon gas mixtures were analyzed to elucidate collisional energy transfer between these gas species occurring in the plasma. In the argon–helium mixed gas plasma, the enhancement or quenching of particular Ar II lines was observed when helium was added to an argon-matrix glow discharge plasma, meaning that a redistribution in the population among the excited levels could be induced through argon–helium collisions. On the other hand, the krypton–helium plasma showed little change in the emission intensities of Kr II lines when helium was added to a krypton-matrix glow discharge plasma, meaning that energy exchanges between krypton and helium excited species occur inactively. These phenomena are principally because the excitation energy as well as the spin multiplicity between collision partners follow both the energy resonance conditions and the spin conservation rule in collisions of the second kind in the argon–helium system, but not in the krypton–helium system. In the argon–krypton and krypton–argon mixed gas plasmas, significant intensity changes of particular Ar II or Kr II lines could not be found; therefore, there were no dominant channels for energy exchanges between argon and krypton species in the mixed gas plasmas.