Self-consistent penning-malmberg trap

Abstract

Self-consistent interaction of electrons with electric fields observed in drive space of velocity spread impulse electron beam in longitudinal homogeneous magnetic field during and after the injecting impulse was investigated. The mechanism by which non-neutral electron plasma is accumulated and confined has been studied. Physical behavior of non-neutral plasma has been studied in various non-neutral particle traps, a typical of which is Penning–Malmberg trap. It is a cylindrical trap where the radial motion of the non-neutral particles is constrained by magnetic field, while the longitudinal motions are constrained by electrostatic potential well. When used as an electron trap, the electrons from a thermal cathode are injected parallel to the magnetic field while the cathode side of the electrostatic well is open. By closing the wall dynamically, the electrons that fail to escape during the well closure are trapped. In our experiments the holding electrostatic walls arise self-consistently, simultaneously with injection of an electron beam in the space of drift. Seized there are those particles that at the moment of formation of the trap were in the space of drift.