Enhanced surface insulating performance for polystyrene by atmospheric pressure plasma jet deposition.

• Using APPJ surface modification, a TiC x O y N z film can be deposited on PS. • The surface withstanding voltage of modified samples are improved by 50%. • The maximum SEY of sample with TiC x O y N z film is approximately decreased to 1.5. Surface flashover at the solid dielectric/vacuum interface is a fundamental physical phenomenon, which restricts the development of pulsed power system and high voltage electrical equipment. The initiation and developing processes of surface flashover at the solid dielectric are associated with electrode-dielectric interface, dielectric surface and other external factors. Especially, the surface charges transport properties that related with surface flashover developing process are determined by the physicochemical of the dielectric surface. Therefore, the surface insulating performance can be enhanced by deposited with appropriate functional films. TiN film has a low secondary electron yield (SEY), which can help to suppress the secondary electron multipactor effect and suppress the surface flashover. In this paper, a preparation method of film contained TiC x O y N z using atmospheric pressure plasma jet (APPJ) is proposed. The experimental devices include AC power supply, plasma jet chamber and gas/precursor system. The AC power supply has a power of 1000 VA and frequency of 20 kHz. The precursor tetraethyl titanate (TTEO) is pumped into plasma jet chamber by argon gas and the working gas is nitrogen. The experimental results show that the maximum SEY of sample with TiC x O y N z film is approximately decreased to 1.5. The flashover voltage of sample with TiC x O y N z film is increased obviously. The morphology of the dielectric surface indicates that the rough surface is introduced after modification. Also, the physical processes of film deposition are investigated by the emission spectroscopic analysis. [ABSTRACT FROM AUTHOR]