Vacuum DC flashover performance improvement by CF4 radio frequency capacitively coupled plasma

The vacuum flashover performance of insulating materials plays an important role in the development of high-voltage insulation systems. Radio frequency capacitively coupled plasma (RF-CCP) is often used for surface modification due to its stability and uniformity. In this paper, silicone rubber is modified by CF4 RF-CCP for the improvement of surface flashover withstanding strength. The surface properties of samples were evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and surface charge accumulation and charge dissipation measurement. The results show that the withstanding strength of SIR samples treated by RF-CCP can be promoted up to 24% in vacuum. It is considered that increased surface roughness and introduction of fluorine-containing functional groups both suppress SEEA process and improve the flashover voltage of materials.