Effect of solenoid magnetic current on the beam extraction of filtered vacuum arc source (FVAS)

Abstract

In this study, a new type of filtered vacuum arc source (FVAS) was designed, which was composed of a torus structure with bending angle of 60°. The radius of torus and plasma duct was 266 mm and 80 mm, respectively, and the total length was 600 mm. The magnet part was composed of one permanent magnet, one magnetic yoke and five solenoid magnets. The cathode evaporation region with a modified magnetic mirror configuration was adapted. The plasma duct was electrically isolated from the ground so that a bias voltage could be applied. The cathode was made of graphite and was 80 mm in diameter. A computer simulation and experiment using the Taguchi method (design of experiment) studied the effects of a solenoid magnet on plasma extraction. The source and extraction magnet affected the arc stabilization. The extraction beam current was maximized with a low value of the source magnet current and a high value for the filtering magnet current. The maximized values of the beam current density of 1.8 mA cm 2 and average deposition rate of 5 Å/s were obtained at the conditions of the arc discharge current, source, extraction and bending magnet were 30 A, 1 A, 3 A and 3 A, respectively.