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-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.