Storage and injection of charged particles in an electrostatic trap

Abstract

Ion confinement in an purely electrostatic ion trap is investigated. The trap consists of two concentric cylinders maintained at a potential difference and two electrically insulated end plates. If the length of the trap is long compared with the radial dimension of the trap, the radial potential distribution is practically logarithmic. The domain of ion confinement is derived by comparing the radial displacements at the apogee and the perigee of an ion orbit with the radii of the cylinders. The effect of a magnetic field superimposed along the trap axis is considered. In addition trapping of externally injected ions is studied numerically. The electrostatic trap is used to advantage, when it is required to store charge particles independent of their charge to mass ratio.