MULTI-TEMPERATURE THERMOPHYSICAL PROPERTIES AND QUENCHING CHARACTERISTICS OF ARC PLASMAS IN SF₆ AND ITS ALTERNATIVE

Gaseous switching arc plasmas near current zero typically deviate from LTE and are often modeled using a two-temperature approach. However, in non-equilibrium plasmas, different energy states may follow separate Boltzmann distributions, each with distinct temperatures. This study calculates the thermophysical properties of SF₆ and C₄F₇N arc plasmas by explicitly considering translational, rotational, vibrational, and electronic excitation temperatures. The results reveal that compared to the conventional two-temperature model (distinguishing heavy species and electrons), the multi-temperature framework leads to measurable changes in plasma properties. The C₄F₇N mixture is more sensitive to multi-temperature effects than SF₆. Additionally, the two-temperature simulation model may slightly underestimate the plasma’s non-equilibrium degree.