Marx generator

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

Repetitive high voltage all-solid-state Marx generator for dielectric barrier discharge pulsed plasma

Abstract: Dielectric barrier discharge (DBD) is used in plasma technology with wide applications, such as ozone generation, depollution of gas stream and surface treatment of plastics. Commonly used power supplies for DBD generate sinusoidal voltages with frequency up to 100 kHz. Recent research shows that apart from a primary discharge occurring at the rising front or during the pulse top, a secondary discharge occurs at the end of the falling voltage flank when unipolar square pulses are used. This excitation method of DBDs improves energy efficiency significantly compared with sinusoidal excitation. In this paper, an all-solid-state Marx generator that can generate nearly rectangular pulses with a DBD load is proposed. It operates at an output voltage of 30 kV, a repetition frequency of 1 kHz and 1 kV DC input voltage successfully. Both the rise and fall times are less than 200 ns, and a maximum pulse-width of 1 us is obtained. A transformer isolated gate drive circuit is employed. This prototype has been applied in gas treatment research using DBD. Preliminary experimental results show that it is able to deliver almost rectangular voltage pulse to resistive load and capacitive load. When driving a DBD load, it can output large current at the rising of a pulse.

Development of a Repetitive Wave Erection Marx Generator

Abstract: A repetitive ten-stage wave erection Marx generator is developed to investigate the electrical characteristics of such compact devices and potentially provide an economical approach to realize the miniaturization of intense electron beam accelerators. Compact design has been made for the generator in order to achieve a proper stray capacitance of the spark gap electrode with respect to the ground in each stage because these proper grounded stray capacitances are critical for obtaining a good wave erection process. This generator is initially resistively isolated for single-shot tests and then changed to inductively isolated for repetitive operation. In single-shot experiments, the generator is tested to be able to deliver a high-voltage pulse of 210 kV and a rise time of about 5 ns on a 90-Omega dummy load at a charging voltage of 40 kV. This result agrees basically with that of the PSpice circuit simulation, which adopts a self-breakdown spark gap model. The preliminary experimental results of repetitive operation show that at a charging voltage of 30 kV, the generator can operate at 8.5 Hz without gas blow-off from the internal spark gaps, producing an output pulse of 150 kV and a rise time of less than 20 ns. Differences in the output pulse waveforms between resistively and inductively isolated configurations are analyzed.

Solid-State High-Voltage Pulse Generator for Low Temperature Plasma Ion Mobility Spectrometry

Abstract: Low-temperature plasma ion mobility spectrometry (LTP-IMS) is the method to identify some materials by measuring concentration of gas phase ions. IMS used in a wide range of laboratory-based biomedical research studies. A nanosecond pulse generator is necessary for LTP-IMS apparatus to enable direct analysis of various chemical compounds without having to evaporate the analyte or seek a solvent or any reagent. In this paper, a dual Marx pulsed generator for LTP-IMS Ionization power supply is proposed based on a new combination of some solid-state switches including insulated gate bipolar transistor (IGBT) and avalanche bipolar junction transistors (BJTs). The compact dual Marx generator is composed of a series of avalanche BJTs and an IGBT as the trigger switch, where its rise time is reduced from 100 to 5 ns by using an avalanche BJT in its command circuit. In this way, a controllable high-voltage pulse generator has designed, built, and tested. The proposed circuit can be used to generate the repetitive high-voltage pulses necessary for low temperature ionization in advanced IMS apparatus. The output voltage has an amplitude of up to 6 kV with pulse widths in the range of 40–1000 ns and pulse repetition rates up to 2 kHz, having rise time and fall time less than 10 ns independent of the load specifications.

A conceptual design for an LMF accelerator module

Abstract: The US Department of Energy has initiated a design study of a Laboratory Microfusion Facility (LMF) that will be used to develop high-gain ICF (inertial confinement fusion) targets. A conceptual design for a light ion beam accelerator, has been developed for a multimodule LMF system based on technology demonstrated on Sandia's Hermes-III accelerator. The LMF accelerator module incorporates 32 linear induction cavities, each operating at 1 MV, to produce an output voltage pulse that ramps from 27 to 32 MV with a peak current of 1.2 MA. The power for the accelerator module is derived from 16 Marx generators that drive 128 4- Omega , 54-ns pulse forming lines (PFLs). Four PFL pulses are combined in each inductive cavity. Nanosecond synchronization of the PFL output pulses is accomplished using KrF-laser-triggered output gas switches and low jitter, self-breakdown water switches. The outputs of the cavities are added in a magnetically insulated transmission line and then delivered to an extraction ion diode. Singly ionized lithium ions are accelerated in the diode. Voltage ramping is used to achieve power compression of the ion beam when ballistically drifted to the ICF target. An equivalent circuit has been developed to model the module from the Marx generator to the ion diode. The timing performance of the gas and water switches has been included in the model to calculate the resulting output waveform and system jitter. >

Einzel lens chopper and behavior of the chopped beam in the KEK digital accelerator

Abstract: The KEK digital accelerator (KEK-DA), which is a small-scale rapid-cycle induction synchrotron (IS), has commenced operation. A permanent magnet $x$-band electron cyclotron resonance ion source serves as the KEK-DA ion source and delivers various ions. A new Einzel lens beam chopper has been developed to provide the necessary pulse width of a few microseconds. The chopper is implemented by applying a rectangular pulse voltage generated by a solid-state Marx generator to the middle electrode of the Einzel lens. Momentum modulation at the bunch head and tail resulting from chopping in longitudinal direction has been observed. This intrinsic property of the chopped pulse has been clearly observed in a long drift (a free run in the circular ring) in KEK-DA.