Results are presented from experimental studies of the dynamics of large-diameter multishell gas puffs imploded by microsecond megampere current pulses. The experiments were conducted on the GIT-12 generator in the regime of microsecond implosion (t imp = 1.1-1.2 μs, I 0 = 3.4-3.7 MA). The influence of the load configuration on the dynamics of current losses and gas-puff radiative characteristics was studied. The correlation between the radial compression ratio (the ratio between the initial and final Z-pinch radii) and the magnitude of the current flowing at the plasma periphery was investigated. The experiments show that, in a multishell gas puff, large-scale instabilities insignificantly affect the gas-puff implosion even over microsecond time intervals and that a compact dense pinch with a relatively high average electron temperature (400-600 eV) forms at the Z-pinch axis. The diameter of the plasma column radiating in the K-shell lines of neon is about 3-4 mm, the K-shell radiation yield being 5-11 kJ/cm. In the final stage of implosion, only a small portion of the current flows through the high-temperature central region of the pinch plasma, whereas the major part of the generator current flows through the residual peripheral plasma.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physics and Astronomy (miscellaneous)