Accession Number:

ADA610589

Title:

Design of a Compact Coaxial Magnetized Plasma Gun for Magnetic Bubble Expansion Experiments

Descriptive Note:

Conference paper

Corporate Author:

NEW MEXICO UNIV ALBUQUERQUE

Report Date:

2009-06-01

Pagination or Media Count:

8.0

Abstract:

The design of a compact coaxial magnetized plasma gun and its associated hardware systems are discussed in detail. The plasma gun is used for experimental studies of magnetic bubble expansion into a lower pressure background plasma as a laboratory model for extragalactic radio lobe expansion into the interstellar medium. The gun is powered by a 120 F, 10kV ignitron-switched capacitor bank. High-pressure gas is puffed into an annular gap between inner and outer coaxial electrodes. The applied high voltage ionizes the gas and creates a radial current sheet. The 100kA discharge current generates toroidal flux and poloidal flux is provided by an external bias magnetic field. Axial J B force then ejects plasma out of the gun. If the J B force exceeds the magnetic tension of the poloidal flux by a sufficient amount then a detached magnetized plasma bubble will be formed. Using a multi-tip Langmuir probe array, a high speed camera and a B-dot probe array, the evolution of this plasma bubble as it interacts with pre-existing low pressure background plasma, is studied. In particular, details of the plasma bubble formation system including the main gun cap-bank power system, gas valve control system, bias flux cap-bank power system, and experimental data are provided.

Subject Categories:

  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE