Plane Waves in an Ionized Gas with Static Electric and Magnetic Fields Present

Abstract

General equations are derived which specify such waves in a first approximation when their amplitudes are small. The equation of condition (19) (i.e. the equation of dispersion) is deduced and the nature of its roots is discussed. It is shown that under suitable conditions some of the roots lead to wave-groups which grow as they progress and others lead to waves which everywhere grow in time. The theory includes as special cases many of the results previously obtained for radio-propagation, ?plasma? oscillations, and the like. Applications are indicated to electric oscillations and noise in discharge tubes, and to cosmic noise.