Study on the Surface Charge Accumulation Characteristics of Insulation Materials in $\text{CF}_{3} \mathrm{I} / \text{CO}_{2}$ Mixed Gas

This study investigates the surface charge accumulation characteristics of bowl-shaped insulators in a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{CF}_{3} \mathrm{I} / \text{CO}_{2}$</tex> mixed gas atmosphere. A scaled-down experimental platform was established to measure the surface charge, examining the influence of voltage amplitude, charging time, and gas mixture ratio. It was found that as the voltage amplitude applied to the insulator surface increased, the amount of charge accumulated at the gas-solid interface also increased, with no significant change in the charge distribution. As the charging time increased, the total charge gradually increased and approached saturation. With higher <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{CF}_{3} \mathrm{I}$</tex> content, the surface charge distribution became more uniform under positive voltage, while under negative voltage, higher <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{CF}_{3} \mathrm{I}$</tex> content made the surface more prone to charge accumulation, forming unlikepolarity charge patches. The scaled-down insulator in a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$30 \% \text{CF}_{3} \mathrm{I} / 70 \% \text{CO}_{2}$</tex> mixture demonstrated charge accumulation similar to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SF}_{6}$</tex> and exhibited excellent charge accumulation suppression characteristics under DC voltage, showing promising application potential.