Abstract
The Ar-SF6 inductively coupled thermal plasma (ICTP) at atmospheric pressure was successfully generated for different SF6 admixture ratios in order to investigate the quenching effect of SF6 injection on thermal plasma from the viewpoint of elucidating a remarkable interruption ability of SF6. Spectroscopic observation was carried out to measure the radial distributions of the radiation intensity of Ar lines and temperature for the Ar-SF6 ICTP. It was found that only 0.5% SF6 injection caused a 1/2 decrease in the radiation intensity and 1000 K decline in the temperature on the centre axis at 10 mm below the coil end. A two-dimensinal hydrodynamic model was developed for Ar-SF6 ICTP to simulate flow and temperature fields on the assumption of the local thermal equilibrium. The results obtained from the calculation indicated that a little SF6 addition to Ar ICTP decreased high temperature area above 9000 K drastically. This temperature decaying tendency agreed with the experimental results.
