Studies on Excitation and Rotational Temperatures of an Oxygen-shielded Argon Microwave Plasma Torch Source

摘要

Excitation(T_ exc) and rotation(T_ rot) temperatures were determined under different conditions for an oxygen-shielded argon microwave plasmsa torch source(OS-Ar-MPT). The T_ exc value, which was shown to be between 4300 and 5250 K under different operating conditions, was calculated from the slope of the Boltzmann plot with Fe as the thermometric species. The T_ rot value, which was in the range of 2100—2500 K, was measured with OH molecular spectra. The influences of microwave power, flow rates of the support gas, carrier gas, and shielding gas, as well as the observation height on T_ exc and T_ rot were investigated and discussed. The detailed results of T_ exc and T_ rot provided a better understanding of the performance of an OS-ArMPT as a source for atomic emission spectrometry.