Estimation of parameters of radio-frequency ion injector with an additional magnetostatic field

Abstract The paper presents the results of theoretical study for the influence of an additional magnetostatic field applied to the radio-frequency discharge region on the operating parameters of radio-frequency ion injector, taking into account the shape of its discharge chamber. The integral characteristics are calculated for three injector configurations: with a cylindrical, conical, and hemispherical discharge chamber. For calculations, we used a mathematical model, in which the charged particle behavior in plasma is described by relations close to magnetohydrodynamic, while the neutral particle distribution is determined using an approximate analytical solution obtained when considering a one-dimensional problem of gas flow in a tube. Simulation was carried out in the COMSOL Multiphysics software package. According to the calculation results, an additional magnetostatic field can improve the ion injector performance with any discharge chamber configuration. The greatest operation efficiency increase was observed with a cylindrical discharge chamber. However, according to calculations, the best performance can be obtained if a hemispherical chamber is used.