Showing papers on "Marx generator published in 1976"

High repetition rate pulsed laser discharge system

Abstract: A high repetition rate pulsed glow discharge system for molecular gas lasers wherein sparks positioned adjacent to the discharge electrodes provide both ionization for the suppression of arcing and high repetition rate switching means for the energy storage circuit. The preferred energy storage circuit is a Marx Generator voltage multiplying circuit.

A Compact, Multiple Channel 3 MV Gas Switch

Abstract: A triggered, pressurized sulfur hexafluoride spark gap has been developed in which multiple parallel spark channels are consistently generated in close proximity to each other. In a test in which the switch drove a 60 ohm, 20 nsec pulse line, an average of four to six channels were created within a diameter of about 3 inches. Each channel was about 3.5 inches long in 175 psig SF6, and the total switch inductance was in the region of 90 nH. Triggering is effected by a field-enhanced electrode placed close to the ground electrode, a configuration known as the V/N switch. The trigger voltage at 3 MV pulse charge is 250 kV. The rms jitter of the switch breakdown is less than 1 nsec. It is expected that the high performance (low jitter obtained with a small ratio of trigger voltage to total voltage) will scale to much higher voltages. The switch used in the developmental tests was designed for oil immersion, and possessed a further novel feature, a pressure vessel that can withstand high electrical stress with good reliability. The pressure wall achieves this performance through the use of a segmented design, and withstood up to 3.75 MV over a total distance of about 8.5 inches.

Liquid Dielectric Pulse Line Technology

Abstract: Liquid-dielectric pulse line technology is an important and rapidly developing aspect of short-pulse, very high power generators, such as those used to accelerate relativistic electron beams. A description is presented of recently completed systems, including the largest present examples of both oil-dielectric and water-dielectric design. Oil-dielectric lines are represented by a recently built system that delivers approximately 9 MV, 250-kA and by AURORA a 14-MV, 2 MJ-system. Water-dielectric lines are represented by reference to OWL II, a 100-kJ, 1- MV system. A brief description is given of general design principles. Mention is also made of the spark gap techniques by which the pulse lines of the systems are switched into their loads. The switches described include triggered multiple channels in the liquid dielectric itself (in both oil and water) and self-closing liquid switches. Triggered and untriggered gas switches can also be used, and these are described. Prepulse switches and the circuits used to control prepulse are also described. Brief descriptions are given of the Marxes used in each of the systems.

Pulsed microsecond high‐energy electron beam accelerator

Abstract: Electron beams delivering up to 60 kA at 1.5 MV with pulse durations of 0.5–1.5 μsec were obtained by connecting a low‐inductance Marx generator directly across a vacuum diode. Beams with up to 44 kJ and conversion efficiencies up to 51% from Marx energy into electron beam energy were obtained.

Design of Very Fast Rise and Fall Time, Low Impedance Megavolt Pulse Generators for Laser Excitation

Abstract: Recent developments in e-beam excited laser systems have led to a requirement for very fast rise and fall time, short pulse, low impedance e-beam generators. Advances in low impedance e-beam generator technology to meet this requirement are discussed. Two advanced design machines have been built — a 2 MeV, 200 kA generator with 10–90% rise and fall times of 10 ns, and a 1 MeV, 100 kA generator with rise and fall times of less than 5 ns. The design of these machines and their measured output characteristics are presented in this paper.

Non-coaxial Marx-bank driver for optical excitation of organic dye lasers

Abstract: Construction details are given for a non-coaxial Marx-bank driver system for optical excitation of organic dye lasers. Coaxial flashlamps are used. The electrical characteristics of the driver system are discussed and performance characteristics for Rhodamine 6G are given. The system performs well for visible dyes.

Fast Marx Generator

Abstract: A compact modular Marx generator of a unique low inductance design for application in oil or gas insulated systems is described and test results presented.

Untriggered Multichannel Oil Switching

Abstract: Experiments on a fast risetime, self-breakdown, multichannel oil switch have given an average switch risetime (10–90%) of 5.7 nsec and an average of 12 arc channels per pulse. The apparatus consisted of a 140 kJ Marx generator which charged an intermediate energy store, an SF6 switch and a series inductor. The inductor was varied to change the rate of voltage rise on the Blumlein and knife edge switch. Data are presented on the simultaneity of breakdown of two switches, the dependence of switch risetime and number of arc channels on dV/dt, and on comparisons with empirical oil breakdown formulae.