Marx generator

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

A Compact Gigawatt Pulsed Power Generator for High-Power Microwave Application

Abstract: Nanosecond square voltage pulse is of wide interest because of its potential military and industrial applications, such as high-power microwave (HPM). In this article, a gigawatt pulsed power generator (PPG) for HPM based on the multistage pulse forming networks (PFNs) with a voltage superposition using the Marx scheme, i.e., PFN-Marx generator, is proposed through the theory analysis, numerical simulation, processing manufacturing, and performance experiment. The PPG consists of the main subsystems of the primary power and pulse modulation subsystems. The primary power subsystem is a modular bipolar dc high-voltage generator based on the ac–dc–ac, high-frequency transformer, and voltage multipliers by using the power electronics switches. It can generate bipolar dc high voltage of $\pm$ 42 kV to charge the PFN-Marx generator. As for the pulse modulation subsystem, the PFN-Marx technique is preferred, which consists of 24-stage and six $\textit{L}$ - $\textit{C}$ sections. To verify the PPG, an experimental prototype is fabricated and tested. It has a characteristic impedance of about 40 $\boldsymbol\Omega$ and can deliver square voltage wave with an output voltage pulse of about 500 kV, full-width at half-maximum (FWHM) of 94 ns, and 10%–90% rise time of fewer than 35 ns, indicating its ability to deliver peak power beyond 6.25 GW. In addition, a transit-time oscillator was connected and can radiate microwave power of 0.8 GW at 12.89 GHz for the cathode voltage of 372 kV and the beam current of 9.3 kA.

Design of Marx generators as a structured eigenvalue assignment

Abstract: We consider the design problem for a Marx generator electrical network, a pulsed power generator. The engineering specification of the design is that a suitable resonance condition is satisfied by the circuit so that the energy initially stored in a number of storage capacitors is transferred in finite time to a single load capacitor which can then store the total energy and deliver the pulse. We show that the components design can be conveniently cast as a structured real eigenvalue assignment with significantly lower dimension than the state size of the Marx circuit. Then we comment on the nontrivial nature of this structured real eigenvalue assignment problem and present two possible approaches to determine its solutions. A first symbolic approach consists in the use of Gr\"obner basis representations, which allows us to compute all the (finitely many) solutions. A second approach is based on convexification of a nonconvex optimization problem with polynomial constraints. We show that the symbolic method easily provides solutions for networks up to six stages while the numerical method can reach up to seven and eight stages. We also comment on the conjecture that for any number of stages the problem has finitely many solutions, which is a necessary assumption for the proposed methods to converge. We regard the proof of this conjecture as an interesting challenge of general interest in the real algebraic geometry field.

An all solid-state pulse generator for raising the hydrophobicity of cotton fabrics

Abstract: The development of super-hydrophobic surfaces is important for basic research as well as various applications, such as stain resistant textiles, anti-biofouling paints for boats, and self-cleaning windshields for automobiles. In this paper, an all solid-state pulsed fluorine plasma generator, which can raise the hydrophobicity of cotton fabrics, is proposed. This generator consists of a DC power source, an inductor and a solid-state Marx generator. The pulse parameters can be easily adjusted. The fluorine plasma is excited under very low atmospheric pressure in a closed chamber. Preliminary experiments are carried out. Experiment results suggest the cotton fabrics treated with this pulsed fluorine plasma show great hydrophobicity.

All solid-state pulsed power generator with semiconductor and magnetic compression switches 1

Abstract: Conventional pulsed power sources using gas switches suffer from short lifetime, low PRF and expensive maintenance cost. Many all solid-state generator topologies have been developed to replace them. Marx modulator utilizing IGBTs as main switches has many advantages, such as variable pulse length and PRF, snubberless operation, inherent redundancy. However, the relatively slow turn-on speed of IGBT influences the pulse rise time of the Marx modulator. In this paper, a newly developed all solid-state pulsed power generator is proposed. This generator consists of a Marx modulator based on IGBT half bridge modules and a magnetic pulse sharpening circuit, which is employed to compress the rising edge of the Marx output pulse. The pulse sharpening circuit is composed of two magnetic compression switches and one peaking capacitor. The experimental results demonstrated the effectiveness of pulse sharpening. The design of IGBT drive circuits and magnetic switches is introduced in detail in this paper.

A BIPOLAR MARX GENERATOR FOR A MOBILE ELECTROPORATION DEVICE M. Sack ξ , R. Stängle

Abstract: Since 2000 a mobile electroporation device has been operated for scientific and testing purposes. Now a breakdown of the insulation at one Marx generator output to ground has occurred due to an electric overstressing. This failure makes a redesign of the Marx generator necessary. For the redesign a bipolar Marx generator with a transient insulation to ground has been compared to one with a fixed center ground connection. The paper describes why the solution with the fixed ground connection is considered to be more suitable for the application in the mobile electroporation device. I. INTRODUCTION During the last few years the electroporation has become an interesting new method for opening the cell membranes of plant cells for industrial applications. Together with industrial partners, Forschungszentrum Karlsruhe has set up some industrial-scale electroporation devices: Since 2002 the sugar company SUDZUCKER AG has been operating a test device for the electroporation of whole sugar beets for evaluation and development purposes with a capacity of 10 tons/h. A larger device is currently being planned, [1]. In 2006 an electroporation device for the treatment of apple mash at a throughput of as well 10 tons/h has been put to operation. And there are many more promising applications, e.g. the electroporation of wine grapes. Although the construction details of the different devices differ with respect to the specific needs of the processing material, like the electric field strength, pulse length and number of applied pulses, and the required throughput, the construction principle of the devices is similar: One or several Marx generators deliver highvoltage pulses to the electroporation reactor at a repetition rate of up to 20 Hz. Inside the electroporation reactor the processing material is contacted to a pair of electrodes by means of water or juice in order to apply the pulses. The peak voltage of the applied pulses is in the order of up to 300 kV, driving a pulse with a peak current between 6 to 10 kA at a pulse length between 1 to 2 µs through the electroporation reactor. The typical ohmic resistance of the electroporation reactor is in the order of 30 to 50 Ohm, depending on the design and the plant material.