A timedependent model for railgun plasma armatures
Abstract
This paper describes a onedimensional, timedependent model for the analysis of railgun plasma armatures. The model assumes that the armature is isothermal, and that the electrical conductivity and degree of ionization in the plasma are uniform and constant in time. The model is applied to the analysis of three problems: (1) armature initiation, (2) armature response to a change in current, and (3) armature response to a change in mass. In each case, the perturbation induces damped oscillation in the armature length and projectile acceleration about the corresponding steadystate value. The period of the oscillations is approximately equal to 3 l(eq)/a(o) where l(eq) is the equilibrium armature length corresponding to the steadystate solution, and a(o) is the acoustic propagation velocity in the plasma. The exponential decay time for the cases studied ranges from 140 to 200 microsec. The impact of transient phenomena on gun performance and diagnostics, as well as plans for additional analyses, are discussed.
 Publication:

American Institute of Aeronautics and Astronautics Conference
 Pub Date:
 June 1987
 Bibcode:
 1987aiaa.confQU...B
 Keywords:

 Armatures;
 Mathematical Models;
 Plasma Generators;
 Railgun Accelerators;
 Time Dependence;
 Isothermal Processes;
 Mass Distribution;
 Steady State;
 Electronics and Electrical Engineering