The physics of devices such as the Penning cell, anode layer ion source, and cylindrical and planar magnetrons is reviewed, with particular emphasis on new developments in the field. These crossed-field discharge devices are specially designed to operate at gas pressures below 10 −2 Torr which makes them attractive for a wide range of applications. Due to effective electron confinement in crossed electric and magnetic fields some of these devices (e.g. inverted magnetron) can even run at pressures as low as 10 −10 Torr. At such low pressures the electron confinement time is much longer than the ion transit time so that the discharge is practically pure electron plasma. The review covers not only the physics of the discharges themselves, but also their interactions with electromagnetic fields. The latter allow additional control over the discharge parameters. Important historical steps in development of E × B discharge devices as well as their characteristics and differences are described and some possible future research directions are discussed.

Formation of complex patterns lateral to the current flow in planar dielectric barrier discharges is investigated experimentally. Digital camera images of discharge patterns are providing telltale clues to the origin of pattern formation in barrier discharges. The images reveal that there are (at least) two mechanisms for pattern formation in these discharge systems corresponding to two types of discharge patterns. Type I patterns are triggered by plasma-electric field interaction at the electrode edge, whereas thermal processes are responsible for the appearance of type II patterns.