Back Corona and Relaxation Time

Where the resistivity of a precipitated layer of dust exceeds a value in the neighborhood of 108 ¿m, the phenomenon of back corona generally occurs. The fact that this is not always the case, however, shows that the phenomenon is not perfectly understood. In 1965, the author introduced to the theory the additional factor of the dielectric constant. This had the effect of making relaxation time the fundamental parameter of back corona, rather than resistivity alone. As a result, it is shown that back corona probably depends on conditions in the gas as well as in the dust.