PPPS-2001 Pulsed Power Plasma Science 2001. 28th IEEE International Conference on Plasma Science and 13th IEEE International Pulsed Power Conference. Digest of Papers (Cat. No.01CH37251) - Conference Table of Contents | IEEE Xplore
Pulsed Power Plasma Science

PPPS-2001 Pulsed Power Plasma Science 2001. 28th IEEE International Conference on Plasma Science and 13th IEEE International Pulsed Power Conference. Digest of Papers (Cat. No.01CH37251)

DOI: 10.1109/PPPS.2001

17-22 June 2001

Digest of Technical Papers PPPS-2001 Pulsed Power Plasma Science 2001 [front matter]

Publication Year: 2001,Page(s):0_1 - 903
Explosively driven magnetic flux compression has been the object of research for more than three decades. Recently heightened interest has been focused on the basic physical mechanisms that determine the performance of helical magneto cumulative generators (MCGs). Two single-pitch helical flux compression generators of different sizes have been tested using current-voltage probes and optical diagn...Show More
In previously reported computational studies of fuse opening switches and other exploding metallic foils, apparent inaccuracies in the constitutive relations for the fuse material limited the accuracy of the modeling. In this paper, we use constitutive property models to re-examine experiments that used flux compression generators to deliver 25-35 MA to a copper fuse. Based upon this preliminary s...Show More
Helical MCG of different types are the basis element of fast energy sources. A capacitor bank is used as a power source of initial energy. Characteristic current pulse rise time (in e-times), produced by such helical MCG, is /spl sim/1 /spl mu/s. The generator is operating on inductive load, the value of which is hundreds of nanohenry. Current from several tens up to hundreds of kiloamperes is pro...Show More
A disk generator with a magnetic flux compression cavity of 240 mm diameter (DFCG-240) is the power base of the EMIR facility. It allows investigations to be performed with less financial expenditure. That is why analysis of DFCG-240 possibilities is of great importance. The influence of disk element quantity in a multi-element module, properties of current conducting materials and value of initia...Show More
Results of experiments with a helical MCG with internal helix diameter of 50 mm, supplied with a step-up transformer, are presented. The cylindrical transformer, located axially with the MCG and consisting of two solenoids, inserted into each other, is used. In comparison with the earlier published MCG, this one is more compact. The transformer allows powering of a high-impedance load of /spl sim/...Show More
In the experiments, performed earlier by the authors, on metal cumulative jets destruction with the current of capacitor banks, almost complete destruction of the whole jet was achieved. In this case cumulative charge was located at a distance from current electrodes, approximately equal to the diameter of a cumulative funnel. A physical picture of the jet destruction in high-current regime lies i...Show More
Factors affecting output characteristics of a conical generator are marked out. Absence condition of flux cut-off at the expense of liner and stator axis misalignment is derived. Two-dimensional gas-dynamic calculations of liner dispersion in the conical generator are performed. Satisfactory agreement of calculations and X-ray radiographic experiments is obtained.Show More
For future research in the area of thermonuclear fusion and physics of high-energy-density VNIIEF is conducting the development of the multifunctional electrophysical explosive complex "EMIR". It is supposed, that with the use of this complex the conditions of thermonuclear ignition in high temperature plasma (/spl sim/0.3 keV) with a lifetime about several nanoseconds, forming during the electrod...Show More
During the operation of magnetic flux compression generators (MFCG), the gas-plasma, shocked by the rapidly expanding armature, could lead to electrical arcing across the gas between the armature and the stator at locations where physical contact between the armature and stator has not yet occurred. This will result in a loss of magnetic flux and a decrease in the electrical efficiency of the MFCG...Show More
The source of high-voltage pulses. described in the paper. is a two-stage sharpening system that consists of a helical explosive magnetic generator and explosive and electroexplosive current opening switches separated by a current transformer. The helical explosive magnetic generator provides a stored energy of 1 MJ at a current of /spl sim/1.5 MA and a rise time of 40E10/sup -6/ s in an inductive...Show More
The paper describes one of the possible approaches to a selection of the main parameters of a multi-sectional helical coil of EMG in order to get the required level of the finite current. Each section of the EMG helical coil operates as an independent element with the given coefficient of current amplification. The rate of the coil turns inductance transfer is increased. The helical EMG is describ...Show More
Helical explosive magnetic generators (HEMG) represent the inductive generators of electromagnetic energy. Operation of HEMG is based on compression of magnetic field, preliminary delivered to the helical coil, by the metal armature, placed coaxially in the coil center and expanding during an explosion. Circuit compression results in a decrease of its inductance, while the magnetic energy and the ...Show More
Tubes of aluminum and copper filled with C-4 high-explosive were tested during this study of the effects of explosive flaws and voids, their sizes and locations, and of the effects of armature machining tolerances on the expansion characteristics of armatures within helical flux-compression generators. Flaws and voids were introduced into the explosive fill of 6061-T6 aluminum armatures during ass...Show More
This paper considers the scheme to supply the MAGO chamber with the help of all inductive shunt. In this scheme the time of flow of the preliminary supply current is reduced as compared with the scheme using the explosive closing switch. When supplying the plasma chamber by the helical EMG. the current of preliminary supply is commutated by the closing switch. In the circuit with the closing switc...Show More
The design of explosive driven ferroelectric generators is presented and experimental data are discussed. The active elements are lead zirconium titanate (PZT) disks with diameter D=25 mm and thicknesses H=2.5 mm and H=6 mm and PZT cylinders with D=21 mm and H=25 mm. The high explosive charge was varied from 4.2 g to 30 g. Two different ways to initiate shock waves in the active elements were used...Show More
The results are presented of experimental studies of explosively driven moving magnet generators. The study was performed with the use of high explosive and propellant charge. The projectiles used were NdFeB cylinders with D = 2.5 cm and H = 1.9 cm. Data are given for amplitude of high current pulses for different designs of the devices. The experiments performed have shown that the best option fo...Show More
Results are presented of investigations of the generation of high-current pulses in moving magnet generators designed as an open ferromagnetic circuit. The experimental study was performed with the use of a light gas gun. The magnetic projectiles were ferromagnetic cylinders having 2.54-cm diameters. Data are given for the amplitude of high current pulses and power in the load for different design...Show More
The results of a five-module disk EMG (with a small amount of HE in each module) testing for a dummy load are described. The paper substantiates the use of a small class disk EMG as the energy source for a test bench intended for experiments on liners acceleration at the currents of /spl sim/15...20 MA with a rise time of 6-8 /spl mu/s.Show More
One of the most effective ways to get the high energy densities state of a substance (pressure and temperature) is a fast compression of cylindrical Al-liners by an ultrahigh magnetic field, used for compression of the materials being studied. VNIIEF has developed a disk explosive magnetic generator (DEMG) with an electrical-explosive way of energy delivery to the load with an imploding liner, tha...Show More
A source of electromagnetic energy made on the basis of two loop generators, supplied by a helical explosive magnetic generator, is described in the paper. A possibility has been considered of the loop generators usage to build up a pulsed power system suitable for condensed liners implosion study.Show More
A semi-empirical model of helical magnetocumulative generators (MCGs) has been developed. Two constants that are independent of the type of helical generator and the nature of the load and a single adjustable variable (the characteristic time) have been identified. To verify this model, calculated results were compared to experimental data for four helical MCGs-the Mark IX, FLEXY-I, EF-3, and Ranc...Show More
A semi-empirical model of helical magnetocumulative generators (MCGs) has been developed and is presented in this paper. A single adjustable variable, called the characteristic time, has been identified and its physical significance is discussed. The model has been applied to four different helical MCGs and the calculated results are in good agreement with the experimental results.Show More
Explosive driven ferroelectric generators (EDFEGs) are compact power sources that have been considered for use as seed sources for magnetocumulative generators, as well as prime power sources. Shock waves generated by high explosives are used to shock depolarize ferroelectric materials, which results in a voltage pulse being delivered to a load. These generators have been experimentally investigat...Show More