The paper presents the results of model testing of the electrically exploded current interrupter (opening switch) designed for the switching system used to release the electromagnetic energy from the inductive storage to the load through a closing switch-discharger. A capacitor bank was used as a source of energy for the inductive storage. Some features of the interrupter were varied in order to increase its reliability and operation speed. The obtained experimental data allowed making recommendations on practical implementation of the opening switch. The optimized version demonstrated a possibility to form current pulses with submicrosecond rise time, up to 100 ns, in the low-impedance loads of the inductive storages. The obtained result is true for the currents of megaampere and multimegaampere level that makes it possible to use the opening switch for commutation of the energy sources with high energy capacity, for example, of the explosive magnetic generators.

The paper presents the results of model testing of the electrically exploded current interrupter (switch) designed for the switching system used to release the electromagnetic energy from the inductive storage to the load through a closing switch-discharger. A capacitor bank was used as a source of energy for the inductive storage. Some features of the discharger were varied in order to increase its reliability and operation speed. The obtained experimental data allowed making recommendations on practical implementation of the opening switch. The optimized version demonstrated a possibility to form current pulses with submicrosecond rise time, up to ~ 100 ns, in the low-impedance loads of the inductive storages. The obtained result is true for the currents of megaampere and multimegaampere level that makes it possible to use the opening switch for commutation of the energy sources with high energy capacity, for example, of the explosive magnetic generators.

One of the directions for achieving thermonuclear ignition is compression of a heated, magnetized plasma by a liner. This concept was developed in the USA at the Z Machine (MagLIF project). To achieve ignition, it is necessary to create a current pulse with an amplitude of 60 MA or higher. The Z Machine produces currents with amplitudes up to 25 MA. The development of more powerful installations is a problem for the future. At the same time, today already, the explosive magnetic generators create the required currents with long current rise times. In this work, based on calculation results of the compression of a hot magnetized plasma, the possibilities of achieving ignition using modern disc explosive magnetic generators are discussed.

There are two known directions of work on the implementation of inertial thermonuclear fusion using Z-pinches. In the first, to achieve thermonuclear ignition, it is proposed to compress the target by indirect irradiation with Z-pinch X-ray radiation. The other direction is to compress the preheated magnetized plasma with a liner. Preheating reduces compression requirements, while magnetization reduces thermal conductivity losses and provides additional heating by α-particles even at low plasma density. This concept is being developed in the United States at the Z machine (MagLIF project). According to existing concepts, in order to achieve thermonuclear ignition in these schemes, facilities are required that can create a current pulse with an amplitude of ~ 60 MA. The most powerful facilities based on capacitor banks—the Z machine—realizes a current of up to 25 MA. The creation of facilities that are one order of magnitude more powerful than the Z machine is a matter of the future. Along with this, explosive magnetic generators (EMG) today already implement the required energy, although with much longer rise time of current pulse. The paper discusses the possibilities of using the EMG to achieve the ignition, the arising problems and ways to solve them.

One of the striking examples of implementation of the magnetic cumulation principle was the creation under Chernyshev's leadership in the 1980s of unique devices, i.e., disk explosive magnetic generators (DEMGs) producing record currents up to 300 MA. Attempts to realize their analogs abroad have not been a success thus far. This paper presents the results of studies that culminated in the creation of a new generation of small class DEMGs with an efficiency of HE energy conversion into magnetic field energy by more than twice the previously achieved level.

A method for reducing the characteristic time of action of the pulse produced by explosive magnetic generators is proposed. An experiment was performed whose results confirm that this method can be used in practice.

The results of the development of a two-dimensional MHD code for carrying out computational studies of the dynamics of plasma current sheath in spherical chambers with a plasma focus are presented. Equations of magnetohydrodynamics with allowance for magnetic field diffusion, thermal conductivity and plasma radiation are used in this work. An implicit scheme is used in the calculation of the magnetic field, which makes it possible to describe the motion of plasma in a low-density region behind the plasma sheath. The formulas that take into account the possible appearance of anomalous resistance in the plasma are used to calculate the plasma conductivity. The neutron yield is calculated with allowance for thermonuclear and beam–target neutron generation mechanisms. The effect of the minimum residual gas density behind the plasma sheath on the cumulation of the plasma sheath is studied. The effects of magnetic field diffusion, thermal conductivity and anomalous plasma resistance on the plasma sheath dynamics are considered. The calculations are performed for two spherical plasma-focus chambers operating with currents up to 1 and 2 MA and neutron yields to 1012 and 1.5 × 1013 DT neutrons, respectively. The comparison of the calculated dependences with experimental data on the current, voltage and neutron yield made it possible to refine the parameters used in the calculations and achieve a satisfactory agreement between the simulation and experiment.

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.

The application of disk explosive magnetic generators (DEMG) to drive cylindrical condensed liners makes it possible to impart to them the velocities higher than those achieved at direct acceleration of the liners by the products of explosion of condensed explosives (HE). One of the ways to increase further the velocities of the liners is to construct the cascade systems. The results of calculations of the conditions required for a magnetic drive of massive liners to velocities 20-50 km/s are presented.

The method to study the isentropic compressibility of substances is presented in [1]. A two-layered liner made of an explored material specimen and of an outer current-carrying aluminum tube is driven by the current of Z-machine. Another aluminum liner serves as an anode. The measurements of velocity of the specimen' inner surface and of the anode' outer surface are necessary in the iterative method. In combination with magnetohydrodynamic modeling and mathematical optimization this allows obtaining current, pressure and density in the specimen. Copper was compressed by the pressure of ~ 1000 GPa. The accuracy of pressure determination is 5.7% and of density determination is 1.8%. The capabilities of the disk explosive magnetic generators to conduct similar research are analyzed.

Magnitnoe Obzhatie (MAGO)/magnetized target fusion (MTF) thermonuclear experiments executed with a goal of producing the target plasma heated up to temperatures of hundreds of electronvolts, intended for subsequent compression by an imploding liner accelerated by explosion products, are reviewed. In MAGO/MTF experiments, plasma chambers were used consisting of two or three compartments connected by narrow nozzles: acceleration cylinder compartment and deceleration/fusion compartments (cylindrical or hemispherical). A technology of plasma chamber laboratory conditioning is described. Neutron and soft X-ray pulses are presented and obtained in experiments with chambers powered by an explosive magnetic generator. Irrespective of the chamber geometry and number of compartments, the X-ray pulse consists of a highly intensive peak with a duration of 1μs and more than a 10-μs-long low-intensity tail. The neutron pulse is time coincident with the X-ray peak. Yields up to 10 13 neutrons were detected in experiments with two-compartment chambers. Three-compartment chambers with an intermediate compartment are believed to be more promising for the compression. The results are described of the latter MAGO-IX experiment, the only successful experiment with the three-compartment chamber, in which the yield of 2 × 10 12 neutrons was detected in the third compartment and the yield in the middle compartment was many times lower.

The paper presents the results of model experiments to test a new field liner driver based on the disk explosive magnetic flux compression generator, results of driver development, and revised two-dimensional magnetohydrodynamic simulations of liner implosion.

This paper discusses one type of power generators—a disk explosive generator with flat disk elements and metal inserts. A technique of numerical simulation of the operation of this generator is proposed. The principle of operation and the design of the disk explosive magnetic generator are described. The results of calculations and experiments are presented.

The paper presents the current status of MAGO research and the basic results of the latest explosive experiments. The program of activities aimed at preparation and conduct of experiments on finish compression of high-temperature plasma generated in the thermonuclear compartment of the electric-discharge chamber will be described.