Plasma Acceleration in Pulsed Ablative Arc Discharges.
Abstract
This program was the second phase of an effort to describe and understand plasma acceleration processes in pulsed ablative plasma accelerators using a continuum MHD approach as the basis for analytic modeling. Concurrent with analytic modeling, an experimental diagnostic effort was also performed so that calculated results could be compared to the measured parameters for evaluation of the applicability and accuracy of the model. Diagnostic measurements performed included magnetic flux density using small coil probes, current distribution using a Rogowski coil, plasma front location and velocity using time of arrival probes, and high speed photography using a high speed framing camera. Data was recorded on a digital memory oscilloscope having appropriate frequency response. An unsteady two-dimensional model of the plasma motion including the dissipative effects of finite plasma conductivity, viscosity, and thermal conductance was postulated. The model included direct coupling of the external capacitor discharge circuit to the plasma via the time variant plasma resistance and inductance. A second order accurate two-step explicit numerical integration scheme was used to solve the resulting five simultaneous parabolic partial differential equations and a second order Runge-Kutta technique was simultaneously used to solve the two simultaneous second order ordinary differential equations for discharge current and potential. Results of the two dimensional diagnostic scan are presented in detail but the results of calculations are not included since various problems with the numerics did not enable performing sufficient analysis to verify or disprove the applicability of the proposed model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 15, 1976
- Accession Number
- ADA027725
Entities
People
- Dominic J. Palumbo
- Martin Begun