Calculation and Analysis on Electric Field of High Gradient Insulator

Abstract

Summary form only given. The dielectric wall accelerator (DWA) is a new accelerator concept particularly suited for short pulse and high currents. High gradient insulator (HGI) is one of the key technologies in DWA, whose breakdown electric field intensity is about 1.5 to 4 times higher than conventional insulators in long pulse, short pulse, and alternating polarity applications. The electric field of HGI in different structures was calculated using finite element method (FEM). The effect of electrodes on electric field distribution was considered in modeling. The electric field of HGI was also compared with that of homogeneous insulator in the same length. In addition, we studied the field distribution differences when the outermost layer of HGI was individually insulation or metal. How the dielectric constant of insulation layer influences the electric field of HGI was analyzed. The field intensity vector, the radial and axial field component of HGI surface was obtained. The study results indicate that the radial electric field plays an important role in micro-stack insulator. It not only changes the electron motion trace to suppress the secondary electron emission, but also releases electron when electric field here is higher than some value. The research provides some references for micro-stack insulator design, and it's also the foundation of further calculation on particle trace.