Electron beam ion source for highly charged ion production in a continuous regime

Abstract

It seems feasible to strip ions to charge state q>20 during two traverses along the high-density electron beam in a continuous regime. The singly charged ions decelerated before the extractor electrode can be injected into the electron beam through the aperture in an electron collector. The further deceleration to thermal energies can be done by the controlled potential on the drift tube, shaping this drift tube and by Coulomb interaction with electrons in a beam. The injected ions travel along the drift tube, decelerate, turn around, and travel back towards the electron collector. We estimate the travel time of ions inside the electron beam with a length of 2m to be τ=(0.5–5.0)×10−3s. With electron beam current density J=1000A∕cm2 the ionization factor can reach Jτ=(0.5–5.0)C∕cm2, which is sufficient for producing ions with charge states of 10–30 (depending on the species). Such device can be efficient for producing ions of short-lived isotopes. It utilizes an electron gun with high electrostatic compression and subsequent adiabatic Brillouin focusing.