Effects of N2 gas addition to Ar or Ne glow discharge plasmas on the observed intensities of the emission lines are investigated, when nitrogen gas is added to Ar or Ne carrier gas. Drastic decreases in the intensities of Ar I, Ar II, Cu I, and Cu II are observed in the Ar-N2 system, whereas only the N2 emission bands that result from the transition, C 3∏u → B 3∏g (second positive system), are very itense. It can be suggested that the population of the Ar metastases (4s [3/2]2, 4s [1/2]0) is reduced by mixing N2 gas through Ar-N2 collisional energy transfer because the energy levels of the metastables are slightly higher than those of the N2 C 3∏u excited states. The metastable levels may serve as energy reservoirs for ionizing Ar atoms or exciting to higher levels. Therefore, Ar I and Ar II and Cu I lines, which are derived from Cu atoms sputtered by Ar+ ions, provide drastic reduction in intensity by adding N2 gas. On the other hand, little quenching of Ne I, Cu I, and Cu II lines is detected by using the Ne-N2 mixture plasmas. Intensity enhancement of the Cu I resonance line at 327.4 nm is observed when N2 gas is added to the Ne glow discharge plasma.
ASJC Scopus subject areas
- Analytical Chemistry