Electric Field-Free Gas Breakdown in Explosively Driven Generators

All known types of gas discharges require an electric field to initiate them. We are reporting on a unique type of gas breakdown in explosively driven generators that does not require an electric field

Electric Discharge Caused by Expanding Armatures in Flux Compression Generators

In this letter, we experimentally demonstrate that explosively driven expansion of metallic armature of the magnetic flux compression generator (FCG) plays a dominant role in the formation of plasma and electric discharge initiation inside the FCG

Explosive-Driven Mini-System Based on Shock Wave Ferromagnetic Seed Source and Loop Magnetic Flux Compression Generator

Completely explosive pulsed power mini-systems based on the transverse shock wave ferromagnetic generator (FMG) served as a seed source and loop magnetic flux compression generator (LFCG) as a pulsed power amplifier were proposed, designed, built and tested. The physical principles and design of the developed FMG-LFCG system are described in detail. Experimental data are presented for the explosive operation and electrical performance of the system

Pulse Charging of Capacitor Bank by Explosive-Driven Shock Wave Ferroelectric Generator

Ultracompact explosive-driven shock wave ferroelectric generators (FEGs) were used as autonomous primary power sources for charging capacitor banks of different capacitance. The FEGs utilized longitudinal (when the shock wave propagates along the polarization vector P) shock wave depolarization of Pb(Zr52Ti48)O3 (PZT) polycrystalline ferroelectric ceramic. PZT disks having diameters ranging from 25 to 27 mm and three different thicknesses: 0.65, 2.1, and 5.1 mm. It was experimentally shown that during the charging process the FEGs were capable of producing pulsed power with peak amplitudes up to 0.3 MW. Results for charging voltage, electric charge transfer and energy transfer from the FEGs to the capacitor banks of capacitances CL = 2.25, 4.5, 9.0, 18.0, and 36.0 nF are presented. Analysis of the experimental data shows that the maximum energy transfer from the FEG to the capacitor bank differs for each type of ferroelectric energy-carrying element, and is dependent upon the capacitance of the capacitor banks

Transverse Explosive Shock-Wave Compression of Nd₂Fe₁₄B High-Energy Hard Ferromagnets: Induced Magnetic Phase Transition

Investigations of the magnetic phase state of Nd2Fe14B high-energy hard ferromagnets under the action of an explosive shock wave traveling across the magnetization vector, M, have been performed. We demonstrate that the transverse shock-wave compression of an Nd2Fe14B hard ferromagnet with pressure at the shock wave front of P = 22.3 GPa causes a hard ferromagnet — to — weak magnet phase transition. Due to this phase transition, the magnetostatic energy stored for an indefinite period of time in the Nd2Fe14B ferromagnet is released within a short time interval and can be transformed into pulsed primary power. Based on this effect we have developed a new type of ultracompact (volumes from 9 to 50 cm3) autonomous explosive-driven source of primary power that is capable of powering a magnetic flux compression generator with current up to 4 kA, and of charging high-voltage Arkadiev-Marx type generator capacitor banks

High Voltage Charging of a Capacitor Bank

We have demonstrated the feasibility of charging a capacitor bank to a high voltage using an autonomous ultra-compact explosively driven source of prime power. The prime power source is a longitudinally driven shock wave depolarization of a ferroelectric ceramic. The energy-carrying elements of the shock wave ferroelectric generators (FEGs) were poled Pb(Zr52Ti48)O3 polycrystalline ceramic disks with 0.35 cm3 volume. FEGs charged 9 nF, 18 nF, and 36 nF capacitor banks and provided pulsed-power with peak amplitudes up to 0.29 MW. The maximum efficiency of electric charge transfer from shocked Pb(Zr52Ti48)O3 elements to a capacitor bank was 46%. We demonstrated experimentally that the FEG-capacitor bank system can perform as an oscillatory circuit. A methodology was developed for numerical simulation of the operation of the FEG-capacitor bank system; the simulation results were in a good agreement with the experimental results

Longitudinal Shock Wave Depolarization of Pb(Zr₅₂Ti₄₈)O₃ Polycrystalline Ferroelectrics and Their Utilization in Explosive Pulsed Power

A poled lead zirconate titanate Pb(Zr52Ti48)O3 (PZT) polycrystalline piezoelectric ceramic energy-carrying element of a compact explosive-driven power generator was subjected to a longitudinal explosive shock wave (the wave front traveled along the polarization vector P0). The shock compression of the element at pressures of 1.5-3.8 GPa caused almost complete depolarization of the sample. Shock wave velocity in the PZT was determined to be 3.94 ± 0.27 km/s. The electric charge stored in a ferroelectric, due to its remnant polarization, is released during a short time interval and can be transformed into pulsed power. Compact explosive-driven power sources utilizing longitudinal shock wave depolarization of PZT elements of 0.35 to 3.3 cm3 volume are capable of producing pulses of high voltage, with amplitudes up to 22 kV, and up to 350 kW peak power

New Concept for Constructing an Autonomous Completely Explosive Pulsed Power System: Transverse Shock Wave Ferromagnetic Primary Power Source and Loop Flux Compression Amplifier

A new design idea for a compact, autonomous, completely explosive pulsed power system is proposed. The system is based on the shock wave ferromagnetic generator (FMG) as a primary power source and a loop magnetic flux compression generator (LFCG) as a pulsed power amplifier. The FMG primary power source utilizes the effect of transverse shock wave demagnetization of Nd2Fe14B high-energy hard ferromagnets to produce the seed current. Results are presented of an experimental study and digital simulation of operation of the FMG-LFCG syste

Transformer-Type Seeding System of a Helical FCG Based on a Transverse Shock Wave Ferromagnetic Generator

A new application of the effect of transverse-shock-wave demagnetization of Nd2Fe14B high-energy hard ferromagnets for powering an explosive-driven helical flux compression generator (FCG) is proposed. The novel FCG seeding system based on a compact transverse shock-wave ferromagnetic generator (FMG) containing a 200-cm3 Nd2Fe14B energy-carrying element and a 12 g high explosive charge was designed, constructed, and tested. The proposed design is based on the idea that the wide coaxial single-turn pulse-generating coil of the FMG can simultaneously serve as a seed coil for the FCG. The coaxial single-turn pulse-generating coil of the FMG was wound on the initial part of the FCG helix; therefore, only transformer coupling existed between the pulse-generating system of the FMG and the helix of the FCG. This seeding system provides up to 180 A current amplitude and 55 mus current pulse duration to a helical FCG

Compact Autonomous Explosive-Driven Pulsed Power System Based on a Capacitive Energy Storage Charged by a High-Voltage Shock-Wave Ferromagnetic Generator

A new concept for constructing compact autonomous pulsed power systems is presented. This concept utilizes a high-voltage explosive-driven shock-wave ferromagnetic generator (FMG) as a charging source for capacitive energy storage. It has been experimentally demonstrated that miniature FMGs (22-25 cm³ in size and 84-95 g in mass) developed for these experiments can be successfully used to charge capacitor banks. The FMGs, containing Nd₂Fe₁₄B energy-carrying elements, provided pulsed powers of 35-45 kW in times ranging from 10 to 15 µs. A methodology was developed for digital simulation of the operation of the transverse FMG. Experimental results that were obtained are in a good agreement with the results of digital simulations