Helical Explosive Magnetic Generator Research Articles

Source of megaampere current with the rise time ∼100 ns on the basis of explosive magnetic generator

To achieve a thermonuclear ignition threshold in the scheme of indirect irradiation of Z‑pinch by X‑radiation, it is necessary to implode the liner by the current with the amplitude 65 МА for the time 100 ns. The currents with such parameters can be achieved with the use of super-power disk explosive magnetic generators and a two-stage current pulse sharpening system based on foil electrically exploded current opening switches in a form of a serpentine. The implementation of the explosive current source with a rise time of 100 ns is advisable to be carried out in stages by increasing the magnitude of current. The results of the first-stage experiments, in which the current with the amplitude of 5 MA was produced on the basis of the helical explosive magnetic generator in the load of 10 nH for the time of 110 ns, are presented.

Source of a Mega-Ampere Current with ~100-ns Time of Rise Based on an Explosive Magnetic Generator

To achieve the thermonuclear-ignition threshold in the scheme of indirect X-ray irradiation of the Z-pinch, it is necessary to implode the liner by a current with an amplitude of ~65 МА within a time of ~100 ns. Currents with such parameters can be generated using super-power disk-type explosive magnetic generators and a two-stage current pulse-sharpening system based on foil, electrically exploded, “serpentine”-shaped current opening switches. It is reasonable to implement the explosive current source with a rise time of ~100 ns in stages by increasing the current magnitude. The results of the first-stage experiments in which a current with an amplitude of 5 MA is used in an inductive load of ~10 nH with a time of ~120 ns on the basis of the helical explosive magnetic generator are given.

Method of generating a mega-ampere current pulse to accelerate a liner by a magnetic field

This paper describes a method and device for generating a mega-ampere quasi-trapezoidal current pulse of given amplitude and duration in a liner load. The experimental device consisting of a current source based on a helical explosive magnetic generator (HEMG) produced a current pulse in the liner load with an amplitude of ≈ 10 MA and controlled duration and current rise and decay times. The use of this source to accelerate cylindrical liners allows the study of the mechanisms of material damage in converging geometry, in which new damage effects may occur due to the multidimensional nature of the loading conditions.

Explosive magnetic source of current with controllable output voltage

The paper describes a small-size explosive current source with controllable output voltage shaping a megaampere current pulse. This energy source comprises a helical explosive magnetic generator and an explosive sectionalized current opening switch and is designed to power gas-discharge chambers of the plasma focus type. Control of the output voltage of the pulsed current source is performed in such a manner that in each of the series-connected sections of the explosive current opening switch, voltage is generated with a given time shift relative to the neighboring section.

Damage growth and recollection in aluminum under axisymmetric convergence using a helical flux compression generator

Damage initiation and evolution, failure, and recollection processes under axisymmetric convergence were studied in the Russian-Damage experimental series, a joint effort between the Los Alamos National Laboratory and the All-Russian Institute of Experimental Physics. A helical explosive magnetic generator was used to drive a cylindrical liner shell to produce shock wave loading of a concentric cylindrical target shell. Shock wave amplitude was controlled by the liner-to-target spacing and by the magnetic field amplitude. Variation of the current pulse duration produced either a single impact, to study damage initiation through failure, or a double impact, to study failure with recollection. Both full and partial recollection of the main crack was obtained. By fielding high-precision diagnostics to measure the dynamic drive conditions and material response and by employing post-shot metallographic analysis, this project produced well-characterized experimental data across a range of damage and recollection levels for the chosen material, aluminum. We present selected experimental results to illustrate the methodology and utility of this experimental technique.

Influence of the Hall effect on the plasma dynamics in an MTF/MAGO chamber

The role of the Hall effect in experiments on the magnetic implosion of a D-T plasma in a cylindrical MTF/MAGO chamber fed from a helical explosive magnetic generator is investigated. The plasma dynamics is simulated numerically by a 2D code developed for solving the set of MHD equations with account of the Hall effect. In simulations, the generator, the break switch, and other units were replaced with LR circuits. It is shown that taking into account the Hall effect provides better agreement between numerical simulations and experimental data.