Study the Effect of Dimensional Design inside the Discharge Tube of an Electrothermal Accelerator on Axial produced Plasma

Abstract

This paper is a study of the effect of the dimensional design factors of the discharge tube inside an Electrothermal Accelerator on the axial plasma produced inside the tube. A theoretical approach has been investigated on the base of our previous experimental researches and on the base of universal researches in this field. A low-pressure coaxial discharge is investigated theoretically on the base of one- dimensional axial fluid model. This type of surface-wave-plasma source is relatively new in comparison to the classical cylindrical plasma column sustained by an electromagnetic surface wave. In the coaxial structure the dielectric tube is filled with air at normal pressure and a metal rod is arranged at its axis. The plasma is produced outside the dielectric tube in a low-pressure chamber by an electromagnetic wave traveling along the plasma- dielectric interface. The plasma is both radially and axially inhomogeneous. In this paper we have investigated theoretically the role of metal rod and dielectric tube radii on the wave and plasma characteristics on the base of one- dimensional axial fluid model