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Solid-state pulsed power systems are characterized by high repeatability, high reliability, long lifetime, free maintenance, and easy usage. Such systems with moderate peak power (100-MW level) are widely applied in the high average power region; however, many issues are still to be researched to obtain GW-level peak power. In this paper, a high power solid-state pulse generator delivering a GW-level quasi-rectangle pulse is developed to investigate the electrical characteristics of the generator: 1) the system design is accomplished based on a reasonable setting of a power compression ratio combining semiconductor switches and magnetic switches and verified via circuit simulation; 2) key technologies such as serially connected thyristor switches, magnetic pulse compressor (MPC), Blumlein type low impedance pulse forming network (LIPFN), and induction voltage adder (IVA) are investigated for subsystem construction; and 3) at present, the experimental results achieved on a dummy load are a peak pulsed power of 5.2 GW, a pulsewidth of 170 ns, a repetitive rate of 20 Hz, and an operation time of 5 s with good waveform repeatability. The generator can be potentially applied for high power microwave (HPM) generation, X-ray sources, and industrial applications such as material surface treatment and pulse electric field (PEF) sterilization. [ABSTRACT FROM AUTHOR]

In this article, a self-breakdown repetitive gap switch based on the graphite electrodes with surface modified by TiC is investigated to improve the scattering of the breakdown voltage. The self-breakdown repetitive gap switch was experimentally studied with the graphite electrodes and two kinds of TiC modified graphite electrodes (hereinafter referred to as TiC-I electrodes and TiC-II electrodes). Results show that the scatterings of the breakdown voltages of the graphite, TiC-I and TiC-II electrodes were 2.49%, 1.80%, and 1.54%, respectively. Compared with the graphite electrodes, the mass losses of TiC-I and TiC-II electrodes are reduced by 50% and 68%. The influence of electrode surface morphology on the switch stability is analyzed based on the mechanism of switch conduction process. Compared with the graphite electrodes, the electric field amplification coefficients of TiC-I and TiC-II electrodes are more evenly distributed, which leads to the more evenly distributed field emission current density. Thus, the breakdown areas of TiC-I and TiC-II electrodes are smaller and the gas breakdown processes are more stable than those of the graphite electrodes, resulting in smaller scattering of the breakdown voltage. The method that decreases the scattering of the breakdown voltage and reduces the mass loss of the electrodes by modifying graphite electrodes surface can greatly improve the stability of the switch, which is of significance to the application of the switch in the compact, long time stable operation of high-power pulse power devices. [ABSTRACT FROM AUTHOR]

In this paper, a compact rep-rate GW pulsed power generator is developed. First, its three key subsystems are theoretically analyzed, engineering designed, and experimentally investigated, respectively. The emphases are put on these four problems: the theoretical analysis of the voltage distribution across the conical secondary windings of the high-coupling transformer, the investigation of the high energy storage density dielectric used in the pulse forming line, the choice of the gas flow velocity of the gas blowing system, and theoretical analysis of the passive stability of the pulsed power generator operated in rep-rate mode. Second, the developed pulsed power generator is described in detail. It has a 0.2-m diameter, a 1.0-m length, and a 20-\Omega wave impedance. Across a 100-\Omega resistive dummy load, it can steadily operate at a 300-kV output voltage in 50-Hz rep-rate and 250 kV in 150 Hz without gas blowing system. The average power is \sim1~kW. Finally, the pulsed power generator is applied to drive a relativistic backward-wave oscillator, generating a high-power microwave with peak output power of 200 MW and duration (full-width at half-maximum) of 5 ns in 150-Hz rep-rate. These efforts set a good foundation for the development of a compact rep-rate pulsed power generator and show a promising application for the future. [ABSTRACT FROM AUTHOR]

Amorphous magnetic core has been widely used in pulsed power technology with applications including plasma science research, high-power microwave generation, and material surface treatment. For different applications, dynamic properties of the magnetic core will vary with stimulated magnetic field which determines by magnetization time and waveform of the driving voltage. In this paper, toroidal amorphous magnetic core ($\Phi ~540$ – $740\times25$ mm) was investigated theoretically, numerically, and experimentally. Specifically, the circuit is analyzed. A high-voltage test stand, which can generate different driving voltages with same components, was designed and developed in our laboratory. Dynamic properties, including magnetic induction change, coercive force and losses, were studied under three different typical waveforms with the same magnetic flux. Driving voltages of the pulses were 12, 12, and 6 kV and the magnetization rates were 0.6, 1.2, and 0.6 T/ $\mu \text{s}$ , respectively. Experimental results show reasonable agreement with the numerical analysis. [ABSTRACT FROM AUTHOR]

Magnetic switches could improve the stability, reliability, repetition rate, and life of pulsed power systems, based on which, a high power, low impedance, and long pulse generator has been investigated numerically and experimentally. The generator accomplishes the power compression and the pulse forming at a relatively low voltage level, consisting of a core-type pulse transformer, a two-stage magnetic compression unit, a low impedance pulse forming network, and magnetic type main switches. A full circuit model was developed using PSPICE software to analyze key factors that influence output characteristics of the generator. Key subsystems were manufactured and experimental research was carried out on the whole system. Preliminary results achieved with a dummy load of 2.5 $\Omega$ show that the output pulse power is about 2.0 GW and the pulsewidth is about 170 ns, which are in reasonable agreement with the numerical analysis. [ABSTRACT FROM PUBLISHER]