Spectroscopy of microwave discharge in liquid C7–C16 hydrocarbons

Abstract

Emission spectra of in-liquid microwave plasma in C7–C16 hydrocarbons were studied in the range of wavelengths from 200 to 800 nm. It was shown that spectra are similar for all studied hydrocarbons. Swan-bands only were observed in the plasma emission. Model of Swan-bands emission was designed for experimental spectra processing. Rotational and vibrational temperatures determined from sequences with v = −1, 0, +1 of C2-bands were 1600 ± 200 K and 7000 ± 2000 K correspondingly. Addition of Ar in the plasma decreased the rotational up to 700 K but did not change the vibrational temperature. It was shown that studied in-liquid microwave plasma is non-equilibrium. Results of electrodynamic modeling of microwave discharge apparatus and some information on the solid phase generated in hydrocarbon plasma processing were presented.