Showing papers on "Marx generator published in 2010"

High-Current Linear Transformer Driver Development at Sandia National Laboratories

Abstract: Most of the modern high-current high-voltage pulsed power generators require several stages of pulse conditioning (pulse forming) to convert the multimicrosecond pulses of the Marx generator output to the 40-300-ns pulses required by a number of applications including X-ray radiography, pulsed high-current linear accelerators, Z-pinch, isentropic compression, and inertial fusion energy drivers. This makes the devices large, cumbersome to operate, and expensive. Sandia, in collaboration with a number of other institutions, is developing a new paradigm in pulsed power technology: the linear transformer driver (LTD) technology. This technological approach can provide very compact devices that can deliver very fast high-current and high-voltage pulses. The output pulse rise time and width can be easily tailored to the specific application needs. Trains of a large number of high-current pulses can be produced with variable interpulse separation from nanoseconds to milliseconds. Most importantly, these devices can be rep-rated to frequencies only limited by the capacitor specifications (usually 10 Hz). Their footprint, as compared with current day pulsed power accelerators, is considerably smaller since LTD do not require large oil and deionized water tanks. This makes them ideally suited for applications that require portability. In this paper, we present Sandia National Laboratories' broad spectrum of developmental effort to design construct and extensively validate the LTD pulsed power technology.

High-Power Pulse Generator With Flexible Output Pattern

Abstract: This paper presents a high-voltage bipolar rectangular pulse generator using a solid-state boosting front-end and an H-bridge output stage. The topology generates rectangular pulses with fast enough rise time and allows easy step-up input voltage. In addition, the circuit is able to adjust positive or negative pulsewidth, dead time between two pulses, and operating frequency. The topology can also be controlled to produce unipolar pulses and other pulse patterns without changing its configuration. With an appropriate dc source, the output voltage can also be adjusted to requirements of different applications. The intended application for such a circuit is algal cell membrane rupture for oil extraction, although additional applications, include biotechnology and plasma sciences, medicine, and food industry. A 1 kV/200 A bipolar solid-state pulse generator was fabricated to validate the theoretical analysis presented in this paper. In addition, to validate the analysis with simulations and prototype tests, biological test were conducted in order to examine the technical value of the proposed circuit. These evaluations seem to suggest that oil production rate from bipolar pulses may double that of an equivalent process with unipolar pulses.

A DC Voltage-Multiplier Circuit Working as a High-Voltage Pulse Generator

Abstract: The intensive use of semiconductor devices enabled the development of a repetitive high-voltage pulse-generator topology from the dc voltage-multiplier (VM) concept. The proposed circuit is based on an odd VM-type circuit, where a number of dc capacitors share a common connection with different voltage ratings in each one, and the output voltage comes from a single capacitor. Standard VM rectifier and coupling diodes are used for charging the energy-storing capacitors, from an ac power supply, and two additional on/off semiconductors in each stage, to switch from the typical charging VM mode to a pulse mode with the dc energy-storing capacitors connected in series with the load. Results from a 2-kV experimental prototype with three stages, delivering a 10- s pulse with a 5-kHz repetition rate into a resistive load, are discussed. Additionally, the proposed circuit is compared against the solid-state Marx generator topology for the same peak input and output voltages.

All-Solid-State Repetitive Pulsed-Power Generator Using IGBT and Magnetic Compression Switches

Abstract: By utilizing power semiconductor switches, especially high-voltage insulated gate bipolar transistors (IGBTs), as main switches, Marx modulators have demonstrated many advantages such as variable pulse length and pulse-repetition frequency, snubberless operation, and inherent redundancy. However, the relatively slow turn-on speed of the 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 discrete IGBTs and a magnetic pulse-sharpening circuit, which is employed to compress the rising edge of the Marx output pulse. The experimental results are presented with a maximum voltage of 20 kV, a rise time of 200 ns, a pulse duration of 500 ns (full-width at half-maximum), and a repetition rate of 5 kHz on a 285- resistive load. The output power of the generator is 2.5 kW, and the average power in one pulse is 1 MW. The design methods of the IGBT drive circuits and the parameter calculation of the magnetic pulse-sharpening circuit are introduced in detail in this paper. The factors influencing the performance of the generator are also discussed.

A 6-MV Pulser to Drive Horizontally Polarized EMP Simulators

Abstract: L-3 Pulse Sciences (L-3 PS) is fabricating a 6-MV biconic pulse generator to drive a horizontally polarized dipole electromagnetic pulse simulator antenna at the Naval Air Systems Command, Pax River. The L-3 PS pulser, i.e., the horizontal fast rise electromagnetic pulser (HFREMP), will replace the Maxwell Laboratories ML-5 pulser. The HFREMP project is funded through the Central Test and Evaluation Investment Program (CTEIP). The CTEIP was established by the United States Department of Defense (DoD) to provide joint initiatives, avoid unwarranted duplication of capability, and increase interoperability through capability improvement projects for the DoD Major Ranges and Test Facility Bases. Like the Physics International Fast Risetime EMP Simulator (FEMPS) 2000, which drives an identical antenna at the Centre d'Etudes de Gramat, France, the HFREMP uses two stages of pulse compression. In fact, output capacitors, output switches, intermediate capacitors, and intermediate switches all use the same type of design as the FEMPS 2000. The Marx generator is of a different lower inductance design, and where FEMPS 2000 has a 2.7-MV Marx pulser in only one side, the HFREMP has a 3-MV pulser in each side of the 150- bicone that is the central part of the antenna. When the HFREMP drives the existing Pax River antenna, which is a variable height antenna (30-18 m), it will produce a 60- to 117.5-kV/m peak at the reference sensor with a waveform similar to that of the ML-5, which produces 47-92 kV/m. The HFREMP has also been considered to drive a bounded wave antenna of a different design, which is a fixed height antenna (30 m), producing at the reference sensor a peak field of over 80 kV/m and a wider more smoothly decaying pulse. The design of the HFREMP is described and compared with the designs of ML-5 and FEMPS 2000. Predictions of its performance into both types of antennas are presented.

High Pulsed Power Sources for Broadband Radiation

Abstract: This paper explains the design and production of two autonomous ultrawideband (UWB) radiation sources. These sources consist of a high-gain broadband antenna that is driven by one of two subnanosecond pulsed power sources. Each source is made up of a Marx generator and a pulse-forming device based on the use of a gaseous spark gap. The first source combines a four-stage 200-kV/34-J Marx generator with a coaxial pulse-forming line. Its main characteristics are an output voltage of 100 kV, a 250-ps rise time, a subnanosecond pulse duration, and a repetition rate of about 40 Hz. The second pulsed source is a ten-stage subnanosecond Marx generator that delivers pulses in the 250-kV/1.5-J range, with a 300-ps rise time and a subnanosecond pulse duration at a pulse repetition rate of 350 Hz. Probes were produced based on capacitive line dividers to measure both the temporal characteristics and the high-voltage (HV) amplitude of the pulses delivered by the pulsed power sources. The antenna, combined with these two pulsed sources, is a traveling-wave antenna called the Valentine antenna. Some mechanical modifications were made to the antenna to improve its dielectric strength. First, a 3-D model of the antenna was created on time-domain electromagnetic software to study the influence of these modifications on its main radiating characteristics. Its high gain and its capability to radiate short pulses without dispersion allow us to achieve a high measured figure of merit (the maximum value of far-field peak-to-peak electric field strength multiplied by the distance). A new method called the Instantaneous Electromagnetic Field Measurement by Signature of a Neutral Object (MICHELSON) method is used to measure the very intense electromagnetic fields that are radiated. The incident field is diffracted by a special small-dimension target. The diffracted field is measured by a conventional low-power UWB antenna. The target that is used has small dimensions, and no cables are used in the field region; thus, the electromagnetic interference that is generated and undergone by the measurement device is considerably limited. The figure of merit that is measured is 436 kV.

Bipolar solid state marx generator

Abstract: A high-voltage bipolar rectangular pulse generator using a high efficiency solid-state boosting front-end and an H-bridge output stage is described. The topology of the circuit generates rectangular pulses with fast rise time and allows easy step-up input voltage. In addition, the circuit is able to adjust positive or negative pulse width, dead-time between two pulses, and operating frequency. The intended application for such circuit is algae cell membrane rupture for oil extraction, although additional applications include biotechnology and plasma sciences medicine, and food industry.

Removal of Indoor Air Contaminant by Atmospheric Microplasma

Abstract: Microplasma has advantages of reducing the power and downsizing the entire plasma system. Decomposition of formaldehyde (HCHO) by a microplasma reactor was demonstrated for improving Indoor air Quality (IAQ). One experimental investigation was one pass treatment (5 L/min) and the other one way with a large volume treatment (500 L/min). Removal ratio of HCHO (initial concentration: 0.8 ppm) in one pass treatment was 96 % at a discharge voltage of 1.3 kV using a high voltage amplifier and a Marx Generator with MOSFET switches as pulsed power supplies. In the case of using the Marx Generator there was any NOx generation. Removal ratio of HCHO (initial concentration: 0.5 ppm) in large volume treatment after 60 minutes was 51% at 1.2 kV when using HV amplifier and considering 41 % natural decay ratio of HCHO. Removal ratio was 54 % at 1.2 kV with Marx Generator and 44% natural decay ratio after 60 minutes of treatment.

The GIMLI: A Compact High-Power UWB Radiation Source

Abstract: This chapter presents the design and performances of a compact, general-purpose, high-power ultra-wideband (UWB) source named GIMLI. The system was designed for dual use, homeland security and military applications. It is powered by a compact, coaxial 12-stage Marx generator with a rise time lower than 25 ns and an operating voltage up to 360 kV. A fast monocycle pulse is sharpened using a pulse former (MPF). The shaper stage comprises a switching module including a peaking and a grounding multi-channel spark gap under a N2 pressure of 6 MPa. The module is followed by a monopulse-to-monocycle converter based on a coaxial Blumlein pulse forming line. The bipolar signal measured at the output of the MPF has a duration shorter than 2 ns with a rise time of 250 ps. The peak-to-peak output voltage is 250 kV on a 50 Ω resistive load. Repetitive operation of the MPF has been experienced with a 200 Hz Tesla transformer developed by the CEA (Commissariat a l’Energie Atomique). Electromagnetic energy is focused by a dedicated antenna. The designed antenna is a TEM half-horn with two ridges which improve the low-frequency focusing. High-power radiation tests show that the field measured at a distance of 9 m from the TEM Horn-antenna is higher than 120 kV/m.

Research on high-stability pulser based on avalanche transistor Marx circuit

Abstract: The merits of the full-solid-state pulser, based on avalanche transistor, are high stability, narrow pulse and short rise-time. But the disadvantage of this pulser is that its output power is low, thus Marx circuit is used to improve the peak-voltage. In this paper, the effect factors of the time-stability and shape-stability are analyzed, some optimizing measures are used to improve the stability, and a high-stability pulser is designed. The pulser’s peak voltage is 2 000 V, pulse width is 5 ns, repetition frequency is higher than 25 kHz, and the pulse width jitter is less than 1% and the peak voltage jitter is less than 1%.

All solid-state Marx modulator with bipolar high-voltage fast narrow pulses output

Abstract: A newly developed bipolar high-voltage modulator topology, based on fully integrated solid-state Marx generator circuit, is proposed for generating fast narrow pulses. The new circuit topology combines the advantages of conventional unipolar all-solid-state Marx modulator concepts, which takes advantage of the intensive use of power semiconductor switches, enables the use of typical half-bridge semiconductor structures. Magnetic ring transformers are used for isolating of charging circuit from high voltage pulse output, which simplified the isolation arrangement. The main factors which affect the rising and falling edge of the output pulses are discussed on the basis of simulations and experimental results. A laboratory prototype is composed of 8 stages and each stage is made of 800 V MOSFETs. The modulator operating at 2 kHz repetition rate gives 2 kV bipolar pulses, with 200 ns pulse width, 53 ns rise time, 70ns fall time and 500 ns relaxation time into a 50 Ω resistive load.

Optimizing Compact Marx Generator Networks

Abstract: Compact high-voltage Marx generators have found wide ranging applications for driving resistive and capacitive loads. Parasitic or leakage capacitance in compact low-energy Marx systems has proved useful in driving resistive loads, but it can be detrimental when driving capacitive loads where it limits the efficiency of energy transfer to the load capacitance. In this paper, we show how manipulating network designs consisting of these parasitic elements along with internal and external components can optimize the performance of such systems.

High voltage pulse generator based on Marx circuit and its application for sterilization

Abstract: High voltage pulse sterilization is a new type of non-thermal sterilization technology whose mechanism is that high intensity pulsed electric field can destroy the cell membrane of bacteria instantaneously, so as to induce bacterial death. Considering the harmfulness of biological slime or biofouling to the circulating cooling water system which is produced by combination of excreta in bacterial life cycle and impurities in water, we design a high voltage pulse device for sterilization based on the Marx circuit, and build a micro-prototype circulating water system. This paper simulated and analyzed the internal electric field distribution of treatment chamber with Maxwell software, and carried out the sterilization experiments. The results suggested that this system had a commendable sterilization effect. Moreover, the high voltage pulse sterilization technology is expected to spread and apply to sterilization and anti-scale for various circulating cooling water system.

High pressure picosecond pulse generator

Abstract: The invention discloses a high pressure picosecond pulse generator, and relates to the structure of the high pressure picosecond pulse generator. The high pressure picosecond pulse generator mainly comprises a power supply system, a marx generator, a peaking switch, a super high-frequency cable, a bottom cutting switch, and a coaxial load. The high pressure picosecond pulse output by the high pressure picosecond pulse generator has the characteristics of adjustable amplitude, changeable pulse width, controllable repetition frequency, compact structure, simple installation, convenient adjustment, stable and reliable work and the like. The high pressure picosecond pulse generator can be widely applied to the industries of communication, radar, medical treatment, geophysical prospecting and the like, and is used as a high pressure picosecond pulse signal source with the known characteristics.

Testing device for residual voltage and electrical current distribution characteristic of whole lightning protector

Abstract: The utility model relates to a testing device for residual voltage and electrical current distribution characteristic of a whole lightning protector, and the testing device is characterized in that the testing device comprises an impact generator body which is provided with a control terminal and two testing interfaces, wherein the control terminal is connected with a measurement and control system; one of the two testing interfaces is connected in series with a harmonic resistor, a harmonic inductor and a voltage divider sequentially; the earthing terminal of the voltage divider is sleeved with a current measuring coil, and is further connected with the other testing interface of the impact generator body; the output terminals of the voltage divider and the electrical current measuring coil are both connected in series with the input terminal of an oscilloscope; the output terminal of the oscilloscope is connected with the measurement and control system through a network; and a sample to be tested is connected in parallel with the voltage divider. Due to the adoption of a 2400kv/360kJ, 12-grade Marx generator and an RLC electric discharge loop as the impact generator body, the utility model achieves the function of integrating residual voltage and electrical current distribution characteristic tests of the whole lightning protector. The testing device can be extensively applied to various lightning protector tests in electric power systems.

A 2MV, <300ps risetime, 100Hz pulser for generation of microwaves

Abstract: HPM WBTS (High Power Microwave, Wide-Band Threat Systems) is a high power, repetitively pulsed, wide-band microwave generator. HPM WBTS microwave capability covers the range of 0.2 to 6GHz in nine frequency bands. E-Field specification at target is 30–110 V/m/MHz depending on frequency. The system is transportable, capable of being set up at remote sites and operating on generator power. The HPM WBTS pulser produces a short ( 2MV negative pulse with a rise-time of 6 insulated edge-plane transfer switch (TS). The TS discharges an oil insulated transfer capacitor which is in turn charged by a low-inductance, compact folded geometry Marx generator. This paper will focus on the design and performance of the Marx, TS, PFLs, oil switching and antenna feed features of the HPM WBTS. An accompanying paper at this conference will describe the overall HPM WBTS system. [1] A detailed description of the pulse power design and electrical waveforms data taken from both computer simulation and field testing will be presented. Radiated E-field measured data are not included.

A low impedance 500kV 2.7kJ Marx generator as testbed for vacuum diodes

Abstract: A low impedance Marx generator was developed as part of a test bed for vacuum diodes of various electrode materials and geometries. The generator supplies sufficient energy to initiate and sustain the typically unwanted plasma formation within the diode; which facilitates the observation of the plasma, current uniformity, and electron current densities of various diode structures. The generator consists of ten stages; each stage utilizes a 220 nF 50 kV capacitor, with a series inductance of ∼20 nH. When charged to the rated voltage of the capacitors the energy density of the complete generator with case, spark gaps, insulation, etc., is 19.2 mJ/cm3; this is roughly the energy density of a typical ceramic doorknob capacitor without any supporting structure or isolation. The energy density of the capacitors utilized in the Marx generator by themselves is 104 mJ/cm3. Fired into a low inductance short, the ringing frequency was measured to be 1.4 MHz resulting in an output impedance of 5.2 Ω. Erection of the Marx required adding forward feeding capacitors as the stray capacitance to ground is smaller than the capacitance (∼ 60 pF) of the low inductance, low profile spark gap switches. The design and construction of this generator are discussed as well as selected experimental results obtained with the generator.

Effects of Pulse Voltage Stimulation on Fruit Body Formation in Lentinula Edodes Cultivation

Abstract: Pulsed high voltage was applied to natural logs for mushroom cultivation to verify an effect of the pulse voltage stimulation on fruit body formation. Inductive energy storage (IES) system was employed to construct a pulsed power generator to generate narrow pulse over 100 kV with compact size. Copper thin fuse was used as an opening switch to interrupt large circuit current in short time. Four stages Marx generator was used to supply a large current to a secondary energy storage inductor. The output voltage of the IES pulsed power generator was 120 kV with 50 ns pulse width at 5 kV charging voltage to the primary energy storage capacitor. The output voltage of 50 ns pulse width was applied to the natural logs of Lentinula edodes (Shiitake mushroom) cultivation as the stimulation for the fruit body formation. The total weight harvested from fifteen logs was 2.29 kg at fifty times 50 kV pulse voltage stimulations and was larger by 1.09 kg at one 50 kV pulse stimulation case. The deviation of the mushroom yield among the logs decreased with the pulse voltage stimulation. The hydrophobic protein, which was predicted to contribute to the fruit body formations, was confirmed to be released from the vegetative hyphae when applying the pulse voltage. Keywords—Pulsed power, electrical stimulation, inductive energy storage, mushroom, Lentinula edodes Corresponding author: Koichi Takaki e-mail address: takaki@iwate-u.ac.jp II. EXPERIMENTAL SETUP Fig. 1 shows the Marx-IES pulsed power generator circuit used for the high-voltage electric stimulation of mushrooms. The IES pulsed power generator basically consists of primary energy storage capacitors C, closing switches GS, a secondary energy storage inductor L, and an opening switch [8]. Copper fuse of 0.05 mm diameter was used as the opening switch to interrupt large current in short time. The four primary energy storage capacitors of 0.22 F were connected in parallel and were charged up using high voltage dc power supply (50 kV maximum voltage). A charging voltage VC of the each primary energy storage capacitor was controlled in range from 5 to 7 kV. After charging up the capacitor, the gap switch GS was triggered externally. The closing switch GS changed the connection of the capacitors from parallel to series. As a result, the voltage was stepped up from VC to 4 VC in same manner to the Marx generator [7]. The fuse length l and the total inductance L of the secondary energy storage inductor and the generator circuit were changed in range from 5 to 20 cm and from 1.3 to 38 H, respectively. The circuit current and the output voltage were measured with Pearson 110A current transformer and Pulse Electronics EP-100K high-voltage probe, respectively. The output signals from the current transformer and the voltage probe were stored with a Tektronix TDS3054B digitizing oscilloscope. The stored data were transferred to the computer for analysis of the electrical properties. Fig. 2 shows typical circuit (fuse) current and output voltage waveforms without connection to the logs at 5 kV charging voltage. The fuse length and the inductance of the secondary energy storage inductor are chosen to be l = 10 cm and L = 10 H, respectively. The time 0 means closing the switch GS. The circuit current starts to flow after closing the switch GS with LC oscillation. The peak value of the circuit current is about 920 A at 0.8 s after closing the switch. After the current peak, the current decreases gradually from 920 to 600 A during 0.3 s. This time duration corresponds to a fuse melting phase. The circuit current is interrupted after fuse melting phase within 100 ns. The output voltage increases rapidly and has a maximum voltage of 110 kV, which corresponds to 22 of an amplification factor defined as ratio of the maximum output voltage to the charging voltage. The pulse width of the output voltage is 50 ns in FWHM (full-width at half-maximum). The high voltage pulse is produced by the total circuit inductance and a rapid current interruption produces a high voltage pulse expressed as dt di L dt di L idt C V v C       1 (1) where i means the circuit current. Fig. 3 shows an experimental setup of the pulse voltage stimulation for the natural log cultivation. The L. edodes mushroom was used as a specimen. Fungi were inoculated in the natural logs around two years before the experiment. The logs dimension was 90 cm in length and 10 cm in diameter. The needle electrode of 3 mm diameter and 9 cm length was driven in the logs 7 cm and subsequently the pulse voltage was applied by the MarxIES pulsed power generator as an electrical stimulation. The resistance of the log was roughly obtained as 10 k using a multi-mater. As the result, a pulse current of 11A in peak amplitude and 50 ns in width flows through the logs when the pulse voltage of 110 kV is applied to the logs. Under the experimental condition, the current flows -D.C. H.V. 5 M 5 M 5 M 5 M 5 M

Effects of statistical characteristics of the output voltage in compact Marx generator on insulation test results

Abstract: Lightning strikes or flashovers of insulation can result in impulse voltages with very short front times of some tens of ns. Power apparatuses are exposed to these voltages. Steep-front square impulse voltage with high accuracy can be generated by applying advanced pulsed power technology. Nowadays, compact Marx generator (CMG) is used for achieving exact results in tests. Considering the fact that the breakdown of spark gap is a statistical process, the delay times of the closing switches are statistical and voltage-dependent parameters. In this paper, taking the statistical behaviour of the breakdown process in spark gaps into consideration, the statistical characteristics of the output voltage have been studied in detail and its effect on accuracy of insulation tests are described.

Solid-state Marx based two-switch voltage modulator for the On-Line Isotope Mass Separator accelerator at the European Organization for Nuclear Research

Abstract: A new circuit topology is proposed to replace the actual pulse transformer and thyratron based resonant modulator that supplies the 60 kV target potential for the ion acceleration of the On-Line Isotope Mass Separator accelerator, the stability of which is critical for the mass resolution downstream separator, at the European Organization for Nuclear Research. The improved modulator uses two solid-state switches working together, each one based on the Marx generator concept, operating as series and parallel switches, reducing the stress on the series stacked semiconductors, and also as auxiliary pulse generator in order to fulfill the target requirements. Preliminary results of a 10 kV prototype, using 1200 V insulated gate bipolar transistors and capacitors in the solid-state Marx circuits, ten stages each, with an electrical equivalent circuit of the target, are presented, demonstrating both the improved voltage stability and pulse flexibility potential wanted for this new modulator.

A resonant based Marx generator

Abstract: The configuration proposed in this paper aims to generate high voltage for pulsed power applications. The main idea is to charge two groups of capacitors in parallel through an inductor and take the advantage of resonant phenomena in charging each capacitor up to a double input voltage level. In each resonant half a cycle, one of those capacitor groups are charged, and finally the charged capacitors will be connected together in series and the summation of the capacitor voltages can be appeared at the output of the topology. This topology can be considered as a modified Marx generator which works based on the resonant concept. Simulation models of this converter have been investigated in Matlab/SIMULINK platform and the attained results fully satisfy the proper operation of the converter.

High-repetition and -stability all-solid state pulsers based on avalanche transistor Marx circuit

Abstract: Ultra-wide spectrum (UWS) pulser, in which avalanche transistor is used as its switch, can generate high-repetition and -stability short-pulse, but its power is sharply lower than that of SOS and Tesla generators. Marx circuit is used to increase the power of this type of pulser. Different charged-capacitance and class of Marx circuit determines different waveform and peak-power of output pulse. 20-class and 30-class avalanche transistor Marx circuit pulsers are designed, and the charged-capacitance is 100pF and 470pF, then 4types of waveform are get. The highest output peak-voltage is 2.9kV, the highest repetition can reach 70kHz, and keep a better pulse stability, jitter is less than 40ps.

A Solid State Marx Modulator that can drive a magnetron in a remote location

Abstract: Most modulators designs can be configured as standalone or in the hybrid configuration using a pulse transformer to increase its output voltage The Solid State Marx is no exception By combining a standard pulse transformer with a Solid State Marx Modulator, the result is a lower cost flexible modulator The unique features of the Solid State Marx, of variable pulse width, fast adjustable rise times, dynamically controlled amplitude, low output impedance and high reputation rate makes it ideally suitable for most modulator applications The low output impedance of a Solid State Marx can drive cables that are impedance matched to the load using a pulse transformer The cables allow the operation of a magnetron or klystron at a considerable distances from the modulator and power source The unique properties of the Solid State Marx enable the core bias of the pulse transformer and heater supply to be located and controlled at the modulator without additional interconnecting wiring to the pulse transformer and load The paper will delineate this unique design of the Solid State Hybrid Marx Modulator and its performance for a remotely located magnetron or klystron

A Solid State Marx Modulator That Can Drive a Magnetron in a Remote Location

Abstract: Most modulators designs can be configured as stand- alone or in the hybrid configuration using a pulse transformer to increase its output voltage. The Solid State Marx is no exception. By combining a standard pulse transformer with a Solid State Marx Modulator, the result is a lower cost flexible modulator. The unique features of the Solid State Marx, of variable pulse width, fast adjustable rise times, dynamically controlled amplitude, low output impedance and high reputation rate makes it ideally suitable for most modulator applications. The low output impedance of a Solid State Marx can drive cables that are impedance matched to the load using a pulse transformer. The cables allow the operation of a magnetron or klystron at a considerable distances from the modulator and power source. The unique properties of the Solid State Marx enable the core bias of the pulse transformer and heater supply to be located and controlled at the modulator without additional interconnecting wiring to the pulse transformer and load. The paper will delineate this unique design of the Solid State Hybrid Marx Modulator and its performance for a remotely located magnetron or klystron.

Traveling-Wave Switches and Marx Generators

Abstract: This chapter considers a possible technique for reducing the rise time of high-voltage switches by placing an array of smaller voltage switches in a traveling-wave geometry. This same technique can also be incorporated in a Marx generator.

Marx generators for high-power RF and microwave applications

Abstract: Recent technological advancements in the field of directed energy have led to increased demand for sources capable of driving high-power RF and high-power microwave (HPM) radiators. APELC's line of Marx generators are uniquely qualified for use in various directed energy applications. Extensive testing performed on a 33-J Marx generator, which has been used as a source to drive various RF loads, will be summarized. Testing included characterizing the thermal behavior of the Marx generator during operation at various pulse repetition frequencies as well as monitoring output pulse characteristics and reproducibility. Pulse characteristics for nine other Marx generators varying from 10 mJ to 1.8 kJ in output energy will also be provided. In addition, measured RF and HPM data from various radiators sourced by APELC's Marx generators will be presented.

High power variable nanosecond differential pulses generator design for GPR system

Abstract: High power variable nanosecond differential pulses generators based on avalanche transistor and Marx Bank are investigated theoretically and experimentally. The circuit employs six avalanche transistors with charging and discharging circuitry for differential pulses generation and step recovery diode, Schottky diode for pulse shaping. The pulse width can be varied from 1ns to 4ns. The pulses amplitude varies from ±30V@1ns pulse width to ±58V@2ns pulse width. The repetition frequency can reach as high as 500kHz. This variable nanosecond differential pulses generator can be used in pulsed GPR system as transmitter and strobe generator in sequential sampling receiver circuit.

Compact and portable, repetitive high peak power generator for an ultra-wideband source

Abstract: The development of an autonomous, repetitive, pulsed power generator is presented. This work is a coordinate effort between CEA, Pau University and Technix to develop a tightly integrated unit, including a battery pack, an intermediate dc/dc converter, a high voltage dc/dc converter, the control system and a high PRF Marx generator. Pau University has designed the Marx generator. They have built a 170 mm diameter, 330 mm length Marx generator capable of delivering 200 kV pulses into 50 Ω impedance with tens nanosecond rise times and a 100 Hz repetition rate, enabling it to drive a pulse forming line and peaking switches. The French Atomic Energy Commission has worked closely with the French company Technix in developing a rapid charging power supply to meet stringent package constraints and still permit high pulse repetition rates. This system has already demonstrated the ability to charge, from DC battery power, a 5 nF capacitance up to 50 kV in 5 ms in a burst of one thousand pulses with 100 Hz repetition rate, delivering a peak power of 3.2 kW. The autonomy is more than 35000 shots or 35 bursts. This generator is equipped with a microcontroller which is remote at a distance up to 75 m with an optical fiber interface. Details of this repetitive peak power generator are presented in this paper. Results of preliminary tests are also included.

Extra low weight FSO system aiming Laser

Abstract: Aiming Laser using for FSO system is considered. Optimization Procedure to minimize weight and size of the Laser is offered. Different schematic designs of Q-Switch Drivers for Pockels Cell based optical arrangement are presented. Schematic solutions of Q-Switch driver design are analyzed. Marx Bank based Generator and High Voltage Switch Schematics are compared. Parameters of constructed Q-Switch Drivers are given.