Accession Number:

ADA220602

Title:

Magnetically Insulation Ion Diode with a Gas-Breakdown Plasma Anode

Descriptive Note:

Corporate Author:

CORNELL UNIV ITHACA NY LAB OF PLASMA STUDIES

Report Date:

1987-06-01

Pagination or Media Count:

17.0

Abstract:

An active anode plasma source has been developed for use in a magnetically insulated ion diode operated on a 10 to the 10th power W pulsed power generator. This source uses an inductive voltage from a single turn coil to break down an annular gas puff produced by a supersonic nozzle. The resulting plasma is magnetically driven toward the radial insulating magnetic field in the diode accelerating gap and stagnates at a well-defined surface after about 300 ns to form a plasma anode layer defined by magnetic flux surfaces. An ion beam is then extracted from this plasma layer by applying a 150 kV, 1 microsec pulse to the accelerating gap. Optimization of the timing of the gas puff, the plasma production discharge and the high voltage pulse has resulted in 1 microsec duration 75-150 keV ion beam pulses with 100 Asq cm peak ion current density over an area of about 400 cm. Up to 5 Jsq cm has been collected by a 4 sq cm calorimeter. The diode impedance history can be varied so that rising, flat, and falling voltage pulse waveforms can be produced. Streak photographs of beamlets impinging on a scintillator and time integrated targets both show beam divergence angles or 3 deg, but under certain operating conditions, large excursions about 25 deg in mean aiming angle on time scales of 20-200 ns are observed.

Subject Categories:

  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE