Marx generator

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

Performance of a compact triode vircator and Marx generator system

Abstract: Vircator high power microwave sources are simple, robust, and require no external magnetic field, making them desirable for use in practical compact high power microwave systems. A vircator can be driven directly from the output of a low-impedance Marx generator, eliminating the need for bulky intermediate energy storage components. A compact high power microwave system has been constructed and tested at Texas Tech University utilizing a triode geometry vircator and a compact Marx Generator. The size and performance of this system is compared to a similar system previously developed at Texas Tech. The current triode vircator is housed within a six inch diameter tube which is eleven inches in length. The Marx is contained in an oil tank that is 36 inches long × 12 inches wide × 18 inches tall. Diode voltage and current, and radiated microwave waveforms are presented.

Conditioning of Carbon Fiber Cathodes in UHV-Sealed Tubes at 200 A/cm 2

Abstract: This paper presents a study on outgassing and electrical conditioning for three carbon fiber cathode types in a vacuum-sealed, high-power microwave virtual-cathode-oscillator (vircator) that operates in the low 10 -9 torr pressure regime. The three cathode types consist of a bare bimodal fiber structure, a bare unimodal fiber structure, and a cesium-iodide coated bimodal fiber structure with identical fiber coverage of 2% by area with a surface area of ~20 cm 2 . The electrodes are cleaned by a 1.2 kW, argon/oxygen microwave plasma prior to complete vircator assembly, followed by a 300 °C bake-out for 72 h. Each cathode was pulsed in a single pulse operation by an 80 J, low inductance Marx generator with an approximate pulsewidth of 100 ns full-width at half-maximum for 10000 current pulses. The data presented includes individual gas constituents, high-speed intensified charge coupled device (ICCD) imaging, and voltage and current waveforms. The conditioning process resulted in a gas load reduction of ~80% overall, with the indication that the bare bimodal fiber structure performed the best as diode power increased throughout the experiment, while the power decreased for the other tested cathode types.

A Compact All-Solid-State Repetitive Pulsed Power Modulator Based on Marx Generator and Pulse Transformer

Abstract: In this paper, a compact all-solid-state pulsed power modulator was designed based on Marx generator and pulse transformer. It is consisted of a six-stage Marx generator using power MOSFETs as switches to generate primary voltage pulses and a pulse transformer through a closed magnetic core to boost and convert the polarity of the output high-voltage (HV) pulse. A MOSFET driver circuit based on optical–electrical isolation was designed for controlling the Marx generator. It shows that the output pulse shapes, especially the rising and falling phases, are determined by the design of the pulse transformer such as its leakage inductance, distributed capacitance, magnetization inductance, and step-up ratio. The designed modulator is able to generate HV pulses with amplitude ranging from −35 to 35 kV, repetition frequency up to 10 kHz, minimum pulsewidth 250 ns. Various types of plasma discharges, including air microdischarge for local treatments, plate-to-plate air dielectric-barrier discharge, underwater discharge, are able to be driven with good reproducibility by this compact pulse modulator.

Multi-megawatt pulsed inductive thruster

Abstract: This invention discloses an engine for use in sustained space travel. The engine is of an electric type powered by a nuclear reactor. The electric engine includes a pulsed inductive magnetic thruster. A gas is discharged against an inductor comprising a series of parallel coils arranged in a spiral fashion. Each coil consists of four separate electrically connected coil sections. Each coil section traverses one-quarter of the distance around the inductor from an outer perimeter to an inner perimeter to form a single closed loop. A capacitor is electrically connected to two outer perimeter connector points for each coil forming a Marx Bank arrangement. All capacitors are charged to full charge and discharged simultaneously by a trigger generator immediately after a puff of propellant gas reaches the inductor. The high induced EMF in the inductor caused by the multiple capacitors in series in a single loop creates a rapidly rising magnetic field which ionizes the propellant gas. The current and magnetic field in the ionized gas drives the gas away from the coil creating the thrust which drives the spaceship.