First and the final fifty nanoseconds of a fast focus discharge

Journal Article · Tue Feb 01 04:00:00 EST 1983 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.864142· OSTI ID:6361571

Decker, G; Kies, W; Pross, G

Conventional plasma focus devices of different capacitor bank energy (kilojoules to megajoules) show very similar discharge behavior with respect to breakdown, compression, and pinch data. The use of SPEED 1: a plasma focus driven by a fast high impedance bank (voltage 200 kV, initial current rise >5 x 10/sup 12/ A/sec, bank impedance 160 m..cap omega..),: allowed the investigation of a 400 nsec discharge in a parameter range not previously accessible. Considerable improvement of current and neutron efficiency (30 A/J; 10/sup 6//J) has been achieved as compared with values (< or =20 A/J; 2 x 10/sup 5//J) of conventional slow devices of equal energy (20 kJ). Exceptional compression dynamics (current derivative spike >10/sup 13/ A/sec FWHM 10 nsec) is observed from electric signals. This is due to the current stabilizing effect of the high bank impedance and especially to improved current sheath structure (reduced thickness, enhanced conductivity). Current density and conductivity of the sheath depend on ignition parameters at breakdown (voltage, current rise), the low values of which are possibly responsible for the similarity of the discharge behavior of conventional devices. Conclusions on further improvements are drawn.

• Research Organization: Physikalisches Institut I, Universitaet Duesseldorf, Duesseldorf, Federal Republic of Germany
• OSTI ID: 6361571
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 26:2; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700106* -- Fusion Energy-- Plasma Research-- Plasma Production-- (-1987)
BARYONS
BREAKDOWN
CURRENT DENSITY
EFFICIENCY
ELECTRIC CONDUCTIVITY
ELECTRIC IMPEDANCE
ELECTRICAL PROPERTIES
ELEMENTARY PARTICLES
FERMIONS
HADRONS
IMPEDANCE
NEUTRONS
NUCLEONS
OPEN PLASMA DEVICES
OPERATION
PHYSICAL PROPERTIES
PLASMA FOCUS DEVICES
PLASMA SHEATH
SIGNALS
STABILIZATION
THERMONUCLEAR DEVICES
YIELDS