Research on the deposition and properties characterization of novel conductive getter films on the inner wall of accelerator vacuum chamber

Abstract

The new generation diffraction-limited storage ring has small vacuum chamber apertures, resulting in a distributed vacuum problem. Depositing a Ti-Zr-V NEG film layer on the inner face of vacuum chambers is an ideal solution for resolving the non-uniform vacuum distribution problem. However, Ti-Zr-V NEG coatings on the surface of the vacuum chamber increase its surface resistivity, which can intensify the wakefield impedance effect. This article proposes adding conductive Ag to the Ti-Zr-V NEG film. A novel Ti-Zr-V-Ag NEG film not only has good vacuum performance, but also has good conductivity. Ti-Zr-V-Ag NEG film is successfully prepared by magnetron sputtering. The activation kinetic processes and surface resistivity of Ti-Zr-V-Ag and Ti-Zr-V NEG films are detected in detail, and comparative research on the activation behavior and surface resistivity of Ti-Zr-V-Ag films deposited with various sputtering pressures is investigated. The results show that adding pure metallic silver to the Ti-Zr-V film effectively decreases the DC resistivity of the NEG films, and this reduction can be further enhanced by reducing the sputtering pressure. The activation kinetics behavior of the Ti-Zr-V-Ag film shows minor degradation compared with that of the Ti-Zr-V film.