Formation of a highly ionized plasma in a capillary discharge with a programmed pulse of input power

Abstract

Summary form only given. A one-dimensional, one-liquid two-temperature magnetic radiative hydrodynamics model of a capillary discharge, in which the physical processes occurring in the plasma and driven by an electrical circuit, are described. In this model all main factors typical for high-current discharges in capillaries were taken into account, including multiple ionized plasma dynamics, radiation transport, and the interaction between the plasma and the capillary wall. Two types of discharges were considered. In one case a capillary is filled by a gas which is first ionized by one way or other so that the discharge develops into a homogeneously created plasma. In the second case, the capillary is in vacuum and a plasma is formed by means of a sliding discharge with evaporation of wall material. To elucidate the operating conditions which lead to the formation of plasma columns with the required dimensions and inner plasma parameters (temperature, density, ionization degree etc.), numerical research of both types of capillary discharges were carried out. Special attention was paid to the influence of parameters and the shape of the input power pulses on capillary plasma characteristics that have not been previously addressed. It is shown that programming the input power pulses is an effective way to create plasma columns with the geometric characteristics and inner parameters required at the creation of active media for x-ray lasers.