Use of magnetocumulative generators in experiments on current disruption of shaped-charge jets

Abstract

UDC 532.52 + 533.95Results of experiments on disruption of shaped-charge jets by a pulsed current are reported. An industrially produced helical-coazial magnetocumulative K-80 generator with transformer energy output was used as a source of energy. The operation of the generator in the experiments performed and the effect of the current-pulse parameters on jet disruption and depth of penetration of a shaped-charge jet into a target are discussed.Introduction. Recently, the process of disruption of metallic shaped-charge jets (SCJ) by an electric current passing through them have been extensively studied both experimentally and theoretically [1][2][3][4][5][6][7][8]. The studies are performed in two directions. In one direction, the SCJ behavior is studied in the high-current regime, and the main goal is to determine the conditions of maximum possible jet disruption and to attain complete disruption. In the other direction, SCJ are investigated in the moderate-current regime. The main goal in this case is to attain partial disruption of SCJ at the least possible energy of the current source, and some jet penetration into the protected target is allowed. In this line of investigation there is a wide spread of the current-source energy required for a specified decrease in the depth of jet penetration into the target. This is due to the fact that development of natural hydrodynamic instability of a jet eventually leads to breakup of the jet into separate fragments. If a SCJ is connected to a current source at time At before the moment of jet breakup, indefiniteness arises in the treatment of the effectiveness of the electric energy AE imparted to the jet during passage of the electric current. For a small value of At, the energy AE can be very low but, nevertheless, the jet is disrupted. It is obvious that experimental results should be compared using a uniform approach to the experimental conditions and experimental facility design.Since in high-current experiments, magnetocumulative generators (MCG) compete with capacitor banks, it is of interest to study the possibility of using them in experiments with SCJ because the explosive character of experiments with MCG is combined with explosion of a shaped charge. The advantages of MCG are their small dimensions and the possibility of producing high energy and current in them. This allows one to use.generators with shaped charges of large and small diameters and to investigate SCJ disruption in both of the above-mentioned regimes.However, there are two significant differences between a MCG and a capacitor bank. In a capacitor bank, electric energy has already been accumulated before closure of the electrodes by a jet, whereas for a MCG, a certain time is required to convert the HE energy into electric energy. Therefore, a mechanism of synchronizing the operation of the shaped charge and the MCG is needed. In addition, since at the same current amplitude, the action integral is as a rule much larger for capacitor-bank discharge than for MCG operation, sharpening of the M...