Compact explosive driven shock wave ferromagnetic generators

The results are presented of tests with compact, explosively driven shock wave ferromagnetic generators. The shock wave from a high explosive charge is passed along the axis of a cylindrical, hard magnet. Two types of permanent magnets were used in the experiments: rare-earth NdFeB cylinders (D = 2.5 cm, L = 1.9 cm) and hard ferrite BaFe/sub 2/O/sub 3/ cylinders (D = 2.2 cm, L = 2.5 cm). The shock wave demagnetizes the cylinder, reducing the flux from the remnant value to zero. This change in flux generates a voltage in the winding. The current generated in the loads of the generators yielded a peak of 0.75 kA. The operation of the shock wave ferromagnetic generators was analyzed by the Maxwell 3D code. An analysis is given on the specific features of pulse generation in a system like this.

I. Introduction

The development of compact, explosive driven pulsed power sources of initial energy is based on four fundamental effects of solid state physics: the piezoelectric effect (generation of electrical charge by a material when it Subjected to pressure forces), the ferroelectric effect (depolarization of a material under the action of a shock wave), the reverse magnetostrictive effect (generation of magnetic field by a material when it deformed) and ferromagnetic effect (demagnetization of permanent magnet by a shock wave). In this paper the results are presented of generation of electric pulses by explosive-to-electric transducers that uses the remnant magneto-static energy existing in hard ferromagnetic materials.