A reactor for the plasma processing of gaseous media, especially internal combustion engine exhaust, has a bed made of a body of ceramic material and electrodes. At least one electrode terminates within the bed at a distance from earthed supporting structure to avoid or reduce the risk of tracking or arcing between the electrode and the supporting structure.
A reactor for the plasma-assisted processing of gaseous media comprising a reactor chamber including a gas permeable bed of active material, a power source for applying across the bed of active material a potential sufficient to establish a plasma in a gaseous medium flowing through the bed of active material and a chamber having an inlet stub and an outlet stub for constraining the gaseous medium to flow through the bed of active material, wherein the bed of active material comprises a matrix of beads of a dielectric material having an assembly of regular arrays of beads in each of which adjacent beads are connected to a high voltage input terminal or an electrical ground.