Marx generator

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

A Low Impedance Marx Generator as a Test bed for Vacuum Diodes

Abstract: A low impedance Marx generator was developed, which will serve as a test bed for Vacuum diodes of various electrode materials and geometries. The vacuum diodes will be used for high power microwave generation. The generator is capable to supply ~3GW of pulsed power to the vacuum diodes which is sufficient enough to produce plasma within the diode for electron beam generation. A vacuum of 10−5Torr is required for virtual cathode formation within the diode, when the beam current exceeds the space charge limiting current. A vacuum diode of reflex triode geometry has been designed and vacuum of 10−5 Torr has been achieved. The repetitive operation of the vacuum diode depends upon the recovery of the diode, the importance of the vacuum system on the recovery of the diode will be explained. A vacuum system with high voltage isolator has been installed for getting the desired vacuum within the diode. The design criterion of the vacuum system will be discussed. The 300kV/1.8kJ Marx generator which will power the vacuum diode has six stages with stage capacitance and voltage of 240nF and 50kV respectively. It has an impedance of ~7 ohm and can deliver 200kV voltage across the diode in critically damped load condition. The generator has a very fast rise time of 200ns.The operational characteristics of the Marx generator are determined experimentally. The results have been analyzed and compared to an equivalent circuit model of the system.

Hydrodynamic Loading of Ceramic Components Due to Pulsed Discharge in Water

Abstract: Pulsed discharge in water produces transient pressure waves. For one kind of high-current electron accelerators composed of a water pulse-forming line and a ceramic-insulated vacuum diode, the mechanical stability of the water-vacuum interface should be taken into account during operations. In this paper, by combining empirical formulas of a plasma-driven water-shock theory with a self-consistent underwater explosive approach, a finite element model was introduced to investigate the shock-wave behaviors. The pressure-time history and ceramic mechanical response to pressure waves were presented. In order to get the pressure profile and verify the calculation models, the arc pressure test, including "point-plane" electrode system, was carried out based on a ten-stage Marx generator. Peak pressures of shock waves were measured by the piezoelectric sensor, and related results have a close approximation to the predictions. The relationship between peak pressure and shock-wave energy under nanosecond time-scale pulsed-discharge condition was also obtained in the experiment. These results may be helpful for the estimation of a water shock when designing structural components of pulsed-power machines.