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Characteristics of a Z-pinch produced from a glass optical fiber

1991; American Institute of Physics; Volume: 3; Issue: 10 Linguagem: Inglês

10.1063/1.859917

2163-503X

E. Figura, Gene H. McCall, A. E. Dangor,

Laser Design and Applications

A Z-pinch discharge in a quartz fiber (20–125 μm diameter) driven by a 150 kA current with a rise time of 50 nsec has been investigated. The pinch was found to develop an m=0 instability during the time of current rise and before the whole fiber had been formed into a plasma. No anomalously stable behavior was seen. The bright spots associated with the instability expanded radially and moved in the axial direction with typical velocities of a few 106 cm sec−1. A coronal plasma was found to exist with density 1016 cm−3 at a radius 500 μm. There was evidence of an energetic (20 keV) electron beam. The observed plasma expansion and ionization agreed well with a one-dimensional magnetohydrodynamic simulation. The simulation showed that the light which was observed to be generated in the core of the optical fiber was due to shock heating. The predicted temperature of the surface of the plasma was also in good agreement with an estimate of the temperature (25±8 eV) obtained by assuming that the light emission was blackbody.