Numerical simulations of foil electrical explosion under helical EMG current drive for Warm Dense Matter generation

Warm Dense Matter (WDM), i. e. substance at densities of the order of that of solids and temperatures of the order of 1-10 eV, can be produced using a helical explosive magnetic flux compression generator (EMG) with an opening switch. A diameter 200 mm EMG with an explosive opening switch can deliver a current of ~5 MA with a characteristic rise time of 0.3 μs to drive thick wires (posts) and study WDM in larger volumes than on stationary facilities. An improved WDM generation system was investigated, in which WDM is produced in cylindrical geometry as a result of an electrical explosion of a thin metal foil, surrounded by an insulator. It is shown that in such a system driven by an EMG with an opening switch one can obtain a large volume of matter with density on the order of (0.01-1) of solid density and temperature about 2-3 eV with better accessibility for electric measurements.

I. Introduction

Warm Dense Matter (WDM) [1] is the state of matter in the range between condensed matter and ideal plasma, which has higher temperature than condensed matter, but lower temperature and higher density than the traditional ideal plasma. In this range, which is often characterized by temperatures of and densities of 0.01 ( is solid density), matter cannot be described by theories applicable to ideal plasma or condensed (solid) matter. Understanding WDM properties is a challenging physical problem, because this state of matter is hard to simulate theoretically or produce/measure experimentally under laboratory conditions. The task of WDM generation is of interest for a wide range of applications. WDM occurs in the core of gas-giant planets, and in engineering and physical applications it forms in systems with fast solid-to-plasma transition, such as exploding wires or quickly heated (by laser or high magnetic fields) materials.