The effect of a transverse magnetic field on glow-discharge created electron beams investigated by electrical probes

Abstract

As known, the hollow cathode discharge has two modes of operation: the usual radial one with low impedance and a high impedance mode in which an axial electron beam is produced. This beam mode occurs at low gas pressures and low discharge currents and the applied discharge voltage determines the energy of the beam electrons. The beam electrons do not suffer collisions with the gas atoms so that they can carry up to 20 % of the whole discharge current. In spite of the spatial compression the beam generation does not lead to the pinching of the background discharge. For advanced technologies it is important to investigate whether or not a relatively narrow and weak magnetic field applied transversely to the electric field at the exit of the hollow cathode (like in a magnetron dc discharge) can control the created electron beam. Indeed, it was found that this transverse magnetic field could have an important effect on the breakdown of the high impedance mode and on the corresponding spatial distribution of the generated electron beam. Some new data about this effect which are obtained under these conditions by using electrical probes are discussed in the present contribution. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.