Peak electrical field strength at hard explosions of conductors

The problems, connected with obtaining high peaked voltages U/sub m/ and electrical field strengths E/sub m/ at hard explosions of foils, when the stored specific magnetic energy essentially exceeds sublimation energy, are considered. Results of the analysis of experimental data and numerical researches showed, that in the locally optimized regimes the above-mentioned quantities are defined mainly by minimal electrical conductivity of explosion products, corresponding to metal-nonmetal-plasma transition. The density at this transition differs from liquid metal density at temperature T/sub b//sup st/ by several tens of percents. In hard regimes the ionizing phenomena and shunting discharge make impossible to receive high value of U/sub m/ and E/sub m/ if the surrounding arc-quenching medium has not enough high electric strength. In case when this electrical strength is sufficient, metal plasma produced by explosion and heated by Joule mechanism does not preclude attainment of high values U/sub m/ and E/sub m/ as it arises after finishing of the phase transition.