Current sheath structures of the plasma focus in the run-down phase

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · IEEE Transactions on Plasma Science (Institute of Electrical and Electronics Engineers); (USA)

DOI:https://doi.org/10.1109/27.62349· OSTI ID:6227993

Kwek, K H; Lee, S ^[1]; Tou, T Y ^[2]

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1. Dept. of Physics, Univ. of Malaya, 59100 Kuala Lumpur (MY)
2. Institute for Advanced Studies, Univ. of Malaya, 59100 Kuala Lumpur (MY)

The current carrying plasma sheath in a 12-kJ plasma focus is studied in the axial run-down phase by means of the Schlieren technique. Subnanosecond ultraviolet light pulses from a preionized, transversely excited, atmospheric nitrogen laser provide sufficiently fine temporal and spatial resolutions for such investigation where the propagation speed of the current sheath is of the order of 10 cm/{mu}s. It is observed that the current sheath grows thicker if it is driven at speeds beyond an optimum value of about 8 cm/{mu}s (when the neutron yield is maximum). The thickening of the sheath is seen as an effect of the ratio of the specific heats. At the speed of 11 cm/{mu}s the effect of the temperature gradient at the electrode surface broadens the sheath further. Slow driving speeds are observed to result in an inefficient and leaky piston.

• OSTI ID: 6227993
• Journal Information: IEEE Transactions on Plasma Science (Institute of Electrical and Electronics Engineers); (USA), Journal Name: IEEE Transactions on Plasma Science (Institute of Electrical and Electronics Engineers); (USA) Vol. 18:5; ISSN ITPSB; ISSN 0093-3813
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700102 -- Fusion Energy-- Plasma Research-- Diagnostics
BARYONS
DIMENSIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FERMIONS
HADRONS
LASERS
NEUTRONS
NITROGEN
NONMETALS
NUCLEONS
PLASMA DIAGNOSTICS
PLASMA FOCUS
PLASMA PRODUCTION
PLASMA SHEATH
PULSES
RADIATIONS
THICKNESS
ULTRAVIOLET RADIATION
YIELDS