Development of overheat instability in the plasma of a high pressure space discharge

Abstract

A hydrodynamic model of quasistreamer breakdown based on the system of equations of magnetohydrodynamics is studied. A third-order linear partial differential equation is obtained for the density disturbance of the plasma neutral component. Cauchy problems for this equation with localized and non-localized disturbances are solved by asymptotic methods (Ludwig's method and the WKB method). In the disturbed domain, anisotropic generation of three modes (one entropy and two acoustic modes) occurs. The short-term solutions obtained give a picture of the development of instability, in satisfactory agreement with experimental data. The absolute instability of the homogeneous plasma of non-selfsustained and selfsustained gas discharge is proved.