Magnetic Field Effect on the Initial Parameters of an Imploding Z-Pinch.

An experiment was performed to study the effect of a magnetic field on the initial radius of a metallic gas-puff Z-pinch with a power-law density profile. The IMRI-5 generator (450 kA and 450 ns) was used as a driver. The preembedded axial magnetic field $B_{z0}$ was varied from 0 to 1.5 T. To determine the initial pinch radius $r_{0}$ , the function $r(t)$ was used that was derived from the time dependence of the pinch inductance $L(t)$. The time-dependent inductance $L(t)$ , in turn, was determined as a function of load voltage $V_{\mathrm{ load}}(t)$ and pinch current $I(t)$. The function $r(t)$ was verified using time-gated optical imaging. Measurements have shown that the initial radius of the metallic gas-puff Z-pinch decreased from 7 to 8 cm at $B_{z0} = 0$ to 2.1–1.7 cm at $B_{z0} = 1.5$ T. The decrease in initial radius $r_{0}$ was accounted for by the effect of the magnetic field on the ion gyroradius. [ABSTRACT FROM AUTHOR]