Imploding Foil Liner Experiments on the MIG Pulse Generator

The energy density in the plasma column formed during the implosion of a cylindrical liner by the current of a powerful generator is largely determined by the radius of the liner. When the liner is accelerated to a given velocity, the liner's initial radius is proportional to the rise time of the generator current. With a current rise time of ~ 100 ns and a liner velocity of ~ 3×10⁷ cm/s (before stagnation), it is necessary to choose a liner radius of about 1 cm. The paper presents experiments on imploding foil liners with a diameter of 1-2 mm when the current front through the liner is sharpened to several nanoseconds. In particular, upon implosion of a 1-mm-diameter liner from 2.5-μm-thick aluminum foil with a current of about 2 MA, a column of plasma with a diameter of not more than 70 μm was obtained. An estimate of the energy density in the plasma column gives ≥ 1.5×10⁸ J/cm³.