V. Mizhiritsky

Study of the Multiwire X‐Pinch as a Load for Mega‐Ampere‐Range Pulsed Power Generators

We present the results of experimental study of the dynamics of plasma formations originated from the high‐current multiwire X‐pinch (the current value up to 2.3 MA) based on the wires of different thicknesses made of different materials

Experimental Modeling on the Recyclable Magnetically Insulated Transporting Lines Aimed at the IFE Reactor

At the Kurchatov Institute, the series of IFE experiments is carried out on the S-300 high-current generator (3 MA, 100 ns, 0.15 Ohm). In this talk, the experimental results on the S-300 machine are presented, related to the study of operation of co-axial magnetically self-insulated transporting line, by the linear current flow density on the inner electrode surface up to j ≈ 7 MA/cm. The specific parameters of this current-carrying line fairly correspond to those of the Sandia Laboratories’ conceptual project of IFE reactor based on the fast Z-pinch [1]. The near-electrode plasma dynamics and its effect on the current transport were studied. The cathode material effect, as well as that of gases and oil layer absorbed by its surface, on the near-electrode plasma dynamics and the current pulse transport along the short MITL segment ware studied too. With respect to the whole project, our conclusion is quite optimistic, to wit, we have found the idea of Recyclable Transporting Lines being adequate to the IFE reactor requirements.

Pulsed power experiments at the Kurchatov Institute aimed at ICF

A series of experiments has been carried out at the linear current flow densities up to 7 MA/cm, aimed at physical modeling of magnetically insulated transmission line of the Inertial Fusion Energy reactor based on the fast Z-pinch. The goals of these experiments were as follows: a) the study of the near-electrode plasma and its effect on the energy transfer; b) determination of the critical MITL parameters to foresee possible restrictions on the efficiency of IFE reactor. The loads were fabricated on the base of foam as profiled cylinders of (3–5) mm in diameter and with 30 mg/cm3 density, with the neck in its central part of about 1 mm in diameter. The goal of this series of experiments was the investigation of plasma dynamics in the Z-pinch neck and the mechanism of neutron generation accompanying the current-driven implosion. The prospects of application plasma opening switches as output cascades of pulsed power generators of megajoule range is studied on base of RS-20 machine. By using the programmed fill the diode gap by plasma, the suppression of pre-pulse has been achieved and shortening the pulse from 40 μs to 100 ns has been obtained.

Experiments aimed at the “Baikal” program

On the S-300 pulsed power generator (4.5 MA, 70 ns, 0.15 Ohm), within the frames of ICF program based on fast high-current Z-pinches, experiments are being carried out studying promising schemes of output units. In particular, a nanosecond-range plasma flow switch is being investigated aimed at sharpening the pulse. As a result, the switching rate as high as 2.5 MA / 2.5 ns has been achieved. The numerical simulation of such a device has been carried out. The results of experiments on the extrinsic magnetic field influence on high-impedance plasma opening switch (POS) operation are reported. It has been demonstrated that the POS output voltage could be increased by the factor of 1.5 compared to the POS free of an extrinsic field. Also the possibility of the expansion of POS conduction phase duration up to 40 µs has been presented. The development of more new laser and nuclear diagnostic methods will definitely contribute to attain new data which could help in understanding the POS operation physics.