Measurement of the absorption cross sections of SiCl₄, SiCl ₃, SiCl₂ and Cl at H Lyman-α wavelength

Atomic resonance absorption spectroscopy coupled with a shock tube is a powerful technique for studying high temperature dynamics of reactive systems. Presently, high temperature pyrolysis of SiCl₄-Ar mixtures has been studied behind reflected shock waves. Using time-resolved absorption profiles at 121.6 nm and a detailed reaction model, the absorption cross sections of SiCl₄, SiCl₃, SiCl₂ and Cl have been measured. Results agree well with available data for SiCl₄ and constitute, to our knowledge, the first measurements for SiCl₃, SiCl₂ and Cl at the Lyman-α wavelength. These data are relevant to silica particle production from SiCl₄-oxidant mixtures combustion synthesis.