Marx generator

About: Marx generator is a research topic. Over the lifetime, 1276 publications have been published within this topic receiving 8970 citations.

High-voltage pulse modulator based on cylindrical self-coupling saturable pulse transformer and solid-state Marx generator

Abstract: High-voltage pulse modulator has broad applications in industry. In order to pursue the qualities of compactness, solidification, and long life time, a high-voltage pulse modulator based on a helical Blumlein pulse forming line (HBPFL),a Marx generator and a self-coupling saturable pulse transformer (SPT) with fully cylindrical coaxial conductors is put forward and investigated in this paper. A new method that the fully cylindrical SPT simultaneously works as the charging pulse transformer and magnetic switch of the HBPFL is put forward and demonstrated. Traditional spark gap is substituted by the SPT to enable the features of solidification, compactness, and long life time of the modulator. Experimental results showed that the SPT had good response characteristics to short sinusoidal pulse and 100 ns-range square pulses. The fully cylindrical SPT driven by the 50–70 kV Marx generator can suppress the saturated inductance of the secondary windings to a level less than 500 nH, due to the strong reversed mutual induction between cylindrical windings after the core saturated. It also demonstrated that the pulse modulator was able to deliver a high-voltage pulse to a 160 Ω load, with amplitude of 148 kV, pulse duration of 130 ns, and pulse rise time ranging from 60 to 105 ns.

Design of a novel gate driver circuit for a Marx generator based 40kV electric fence energizer

Abstract: Marx generator is a High Voltage Pulsed Power Supply (HVPPS) technique that consists of switches and capacitors. This paper considers design of a Marx generator consisting of 100 stages for a 40kV non-lethal electric fence. The gate drivers for the employed semiconductor switches have to meet the requirements of synchronized switching and high voltage isolation up to 40kV. Gate driver schemes generally used for Marx generators employ optocouplers and pulse transformers. To meet the requirements, these schemes result in costly, bulky and complex circuits when implemented for a large number of stages of a Marx generator making it an unattractive choice for low power applications (such as an electric fence) despite its many superior features over other HVPPS schemes. Electric fence application has an additional requirement of controlled release of energy to the output to ensure non-lethal behavior. Therefore, a novel gate driver design is presented here which is compact, economical and also ensures control over output energy, hence making Marx generator an attractive design option for electric fence applications. The proposed novel gate drivers were simulated and implemented in hardware for 100 stages to generate 40kV pulses of 15μs at repetition rate of 100Hz with each pulse delivering up to 18mJ energy. The reliability of the systems was tested for a successful continuous run of 10 hours.

A self-closing water switch for load decoupling

Abstract: One of the most popular methods of generating high voltage impulses is to employ a Marx generator. In general, the output voltage pulse of a Marx generator can rapidly energise a pulsed power load in a few tens of ns, depending upon the load capacitance, and thereafter the pulse will decay with a time constant determined by the rate of charge removal from the generator. In some applications, the Marx generator may be required to apply a fairly constant voltage for only a few hundred of ns. This can be achieved by increasing the discharging time constant of the impulse generator to a few /spl mu/s. However, the long wavetail of the impulse waveform in this situation may become damaging to the load after a few hundred ns, and in this case a crowbar circuit is usually incorporated into the system in order to isolate the load. This paper reports on work which was undertaken to develop a simple high voltage switch which can operate as a crowbar device to divert the energy contained in the Marx wavetail away from sensitive loads following the period of interest. The work describes the design and characterisation of a water filled switch developed for this purpose.

Table-Top Soft X-ray Ar+8 Lasers Excited By Capillary Z-Pinches

Abstract: The present study demonstrates Ar+8 laser operation without using any external low-current pre-ionization circuit. Instead, the pre-ionization of the argon gas was provided by automatic pre-ionization via the so-called gliding discharge on the internal surface of the capillary driven by the main excitation circuit. Such a technique considerably simplifies the laser device; the use of the relatively low voltage (200 kV) of the main excitation pulse allowed the use of a gas (SF6 or air at atmospheric pressure) as an electrical insulator in the Marx generator instead of the unpractical biodegradable transformer oil. The reduction of the voltage and current of the main excitation pulse also reduced the ablation of the electrodes and capillary walls increasing their lifetimes. The rest of the chapter is organized as follows. Section 2 describes the basic physical operation principles of Ar+8 lasers. The main physical processes in the laser medium (capillary z-pinch plasma) are described. The main plasma parameters, such as the temperature, density, length, diameter and homogeneity required for the saturated operation of the Ar+8 lasers are analyzed. The methods and techniques providing the experimental realization of the plasma parameters required for Ar+8 laser operation are described in section 3. The experimental results are also presented with a brief discussion of perspectives for future research.