Numerical simulation of electrical explosions in megagauss magnetic fields

The paper reports on a magnetohydrodynamic simulation of electrical explosions of conductors in megagauss magnetic fields. It is shown that in a plane geometry, the time of plasma formation at the surface of a metal conductor does not depend on the rate of rise of the magnetic field and is determined by the properties of the metal; the absolute values of the magnetic field at which plasma is formed are 5±0.25 MGs for copper, 4.25±0.2 MGs for tungsten, 3.85±0.15 MGs for aluminum, and 3.6±0.25 MGs for titanium. In cylindrical geometry, the time of plasma formation does depend on the rate of field rise

The Initial Stage of Neck Formation in an Х-Pinch

A model is proposed to describe the initial stage of neck formation in an X-pinch that proceeds in three stages: the electrical explosion of metal wires that generates the X-pinch; the expansion of the wire material that occurs due to an excess of the gas-kinetic pressure over the pressure of the magnetic field. The model allows one to predict the minimum rate of current rise at which the formation of a "hot spot" in an X-pinch is possible. The minimum current rise rate is determined by the thermodynamic parameters of the wires at a critical point; it is of the order of 1 kA/ns

Study of thin metallic film explosion in vacuum

An experiment with Al, Cu and Ni exploding foils was carried out at a current density of (0.5-1)•108 A/cm{2} through the 6-[mu]m foil with a current density rate of about (0.5-1)•108 A/cm{2} centerdots. To record the metal foil effervescence during the foil explosions, a two-frame radiographic system was used. It was shown that the duration of the explosion resistive phase was considerably lower than the metal boiling time. The foil energy deposition is equal to 30-70% of the sublimation energy