A high-frequency semiconductor generator of high-voltage nanosecond pulses

A high-frequency generator of high-voltage nanosecond pulses based on an assembly of drift step-recovery diodes is described. A circuit that includes parallel transistor chains for the formation of forward and reverse currents of drift diodes is presented. The results of tests of this generator are presented. Voltage pulses with an amplitude of 2.5 kV, a duration of 2 ns, and a pulse repetition rate of 300 kHz were obtained across a 50-Ω load.     

A compact repetitive high-voltage nanosecond pulse generator for the application of gas discharge

Uniform and stable discharge plasma requires very short duration pulses with fast rise times. A repetitive high-voltage nanosecond pulse generator for the application of gas discharge is presented in this paper. It is constructed with all solid-state components. Two-stage magnetic compression is used to generate a short duration pulse. Unlike in some reported studies, common commercial fast recovery diodes instead of a semiconductor opening switch (SOS) are used in our experiment that plays the role of SOS. The SOS-like effects of four different kinds of diodes are studied experimentally to optimize the output performance. It is found that the output pulse voltage is higher with a shorter reverse recovery time, and the rise time of pulse becomes faster when the falling time of reverse recovery current is shorter. The SOS-like effect of the diodes can be adjusted by changing the external circuit parameters. Through optimization the pulse generator can provide a pulsed voltage of 40 kV with a 40 ns duration, 10 ns rise time, and pulse repetition frequency of up to 5 kHz. Diffuse plasma can be formed in air at standard atmospheric pressure using the developed pulse generator. With a light weight and small packaging the pulse generator is suitable for gas discharge application.     

A high-voltage pulse generator for electric-discharge technologies

The electric circuit and design of a high-volta ge pulse generator with an output voltage of ≥3 50 kV is described. The generator operates in the nanosecond range of pulse durations (~300 ns) at a repetition rate of up to 10 pulses/s in a continuous mode and is intended for electric-discharge technologies. The energy stored in the generator is ~600 J, and the energy released in a pulse is ≥300 J. A discharge of a capacitive storage through a toroidal pulsed transformer and a discharge gap is used in the generator.     

A nanosecond SOS-generator with a 20-kHz pulse repetition rate

A nanosecond SOS-generator with a 20-kHz pulse repetition rate in the continuous operating mode and with a 100-kHz pulse repetition rate in the pulse burst mode is described. The generator contains a low-voltage module with a primary capacitive storage and a transistor switch, and a high-voltage module with a magnetic compressor and a semiconductor opening switch (SOS diode). The generator forms pulses with amplitudes of 40–100 kV with a 20- to 30-MW peak power and a 10- to 14-ns duration across a 50- to 500-Ω external load. The output average power in the continuous operating mode is 5 kW. The electric circuit, principle of operation, and design of the generator’s elements are described. The test results are given.     

An Experimental Complex for Studying the Pulse-Periodic Diffuse Discharge Used for the Sterilization of Medical Instruments

An experimental complex for studying the processes that govern the initiation of a diffuse discharge was developed. The complex contains gas discharge chambers with various electrode systems and a high-voltage pulse-periodic generator. A specific feature of this complex's power supply system is that the dc bias-voltage source and the pulse generator can be used simultaneously. The pulse-periodic generator is based on a pulse transformer and a high-voltage shaper of nanosecond pulses with an amplitude of up to 120 kV and a rise time of <10 ns.     

A nanosecond SOS generator with a peak power of 4 GW

A high-current nanosecond generator with a peak power of up to 4 GW, an output voltage of 0.4–1 MV, a pulse duration of 8–10 ns, and pulse repetition rates of 300 Hz in a continuous mode and up to 1 kHz in the burst mode is described. The average output power at a pulse repetition rate of 1 kHz reaches 30 kW. The generator has an all-solid-state energy-switching system. A semiconductor opening switch on SOS diodes forms output pulses. The electric circuit and design of the generator are described, and the experimental results are presented. A device for eliminating prepulses across the load is proposed. The results of its testing and numerical simulation are presented.     

A high-voltage nanosecond pulse generator for exciting diffuse gas discharges at atmospheric pressure

A high-voltage nanosecond pulse generator intended for studying diffuse discharges in gases at pressures close or equal to atmospheric pressure is described. The generator produces pulses with an ∼50-ns (at half-height) duration, a >50-kV voltage amplitude, a 10- to 12-ns rise time, and a pulse repetition rate of up to 1 kHz across an equivalent load (1.3 kΩ, 15 pF). The generator is based on available cheap components, and the amplitude (energy) of output pulses and their repetition rate can be promptly regulated in a wide range. The generator is immune to noise and reliable.     

A generator of high-voltage nanosecond pulses with a subnanosecond rise time

A generator of high-voltage pulses of nanosecond duration with a subnanosecond rise time is described. The generator contains a nanosecond-pulse shaper based on an assembly of drift step-recovery diodes (DSRDs) connected in series and a sharpening switch based on an assembly of deep-level dynistors (DLDs) connected in series. The results of tests of this generator at a pulse repetition rate of 100 Hz are presented. Voltage pulses with an amplitude of 20 kV, a rise time of 0.3 ns, and a duration of 10 ns are formed across a load with a resistance of 50 Ω.     

A high-current nanosecond electron accelerator with a semiconductor opening switch

A compact nanosecond electron accelerator with an output energy of up to 4000 keV, a pulsed power of 100–180 MW, a beam current of 0.25–1.1 kA, and a pulse energy of 5–7 J is described. The accelerator operates with a pulse repetition rate of 200 Hz and ensures an average beam power of up to 1 kW. A nanosecond generator with a solid-state switching system, which is based on magnetic stages of pulse compression and a semiconductor opening switch, is used as a supplying device. The design and electric circuit of the accelerator are described, and test results are presented.     

A SOS-Generator for technological applications

A solid-state nanosecond SOS-generator for electrophysical technology applications is described. In the input part of the generator, the energy arrives at the high-voltage magnetic compressor through IGBT modules and a step-up pulse transformer. The input part of the generator is equipped with an unused energy recuperation circuit, and, when the output pulse is formed, the microsecond pumping mode of the semiconductor opening switch (SOS) is realized. As a result, the complete efficiency of the generator operating into a matched load is increased from ∼40 to 60–62%. The other characteristics of the generator are as follows: the peak voltage is up to 60 kV, the current is up to 6 kA, the pulse duration is about 40 ns, the pulse repetition rate in the continuous mode is 1 kHz, and the average output power is up to 9 kW.     

A compact high-voltage pulse generator with opening insulated-gate bipolar transistor switch and a high pulse repetition rate

A small-size high-voltage (～20 kV) microsecond pulse generator, which is based on a pulse transformer and loaded into a reactor with a pulse corona discharge, is described. Insulated-gate bipolar transistors (IGBTs) that form the switch are used in the low-voltage circuit of the generator. When the switch is open, voltage pulses with an amplitude of up to 1000 V are created across it and, hence, across the primary winding of the transformer. The pulse repetition rate of the generator is ～20000 pulses/s.     

A generator of high-power nanosecond pulses based on a modular two-level summator

A modular approach to designing generators of high-power high-voltage nanosecond pulses on the basis of a two-level wave summator and transistor formers of partial pulses is considered. The design and parameters of the modules that are oriented at the development of generators of voltage pulses of up to 300 kV at a current of up to 4 kA are described. The capabilities of these modules are demonstrated based on the example of a pulse generator with a power of 10 MW, a varied pulse duration of 50–150 ns, and a pulse repetition rate of up to 2 kHz.     

A high-voltage semiconductor rectangular-pulse generator for powering a barrier discharge

A semiconductor rectangular-pulse generator with smoothly controlled output parameters for powering a barrier discharge was developed and investigated. The generator allows the formation of voltage pulses with the smoothly regulated amplitude (0–16 kV) and duration (600 ns–1 ms) across the discharge gap. The pulse rise and fall times can be varied from 40 ns to 1 μs. The generator pulse repetition rate can be smoothly varied from 0 to 50 kHz. The generator can operate in the manual-triggering mode and in the mode of pulse trains with an effective frequency of up to 500 kHz. The generator is intended for initiating and investigating a barrier discharge in millimeter-wide air gaps at the atmospheric pressure.     

A barrierless pulse discharge cell

A barrierless plasmachemical ozone generator, operating on the corona discharge, is studied. A high-voltage pulse power source and a discharge chamber are its basic elements. For obtaining high-voltage pulses with duration of several tens nanoseconds, a rotating discharger is connected to the output of a highvoltage direct-current source. The studied barrierless discharge chamber is characterized by a high efficiency of ozone synthesis, design simplicity, and minimal sizes. As compared to discharge chambers of other types, its advantage is that a corona discharge virtually fully fills its volume. Due to this fact, ozone is synthesized almost in the whole volume of the discharge chamber, resulting in attaining its high concentration at the chamber output. A productivity equal to 30 g/m³ and higher was reached in the experiments.     

Operation mode of the proton injector in the linac of the Institute for Nuclear Research with a 100-Hz pulse repetition rate

Results of the analysis and upgrading of the high-voltage pulse generator circuit in the proton injector for operation with a 100-Hz pulse repetition rate are presented.     

An electrohydraulic installation

An installation using the electrohydraulic effect is designed for investigation of physicochemical processes running in liquids under the action of high-voltage electric discharges. A control unit allows one to vary the discharge voltage (from 1 to 40 kV), current (10–150 kA) duration of the discharge pulse (from 0.3 to 2 μs), and the pulse repetition rate (from 0.1 to 10 Hz).     

A Nanosecond High-Voltage Periodically Pulsed Generator Based on a Helix Forming Line

A nanosecond high-voltage periodically pulsed generator based on a helix forming line is described. The line is charged from a high-coupling Tesla transformer. Compared with a conventional coaxial line, the helix line provides a fourfold increase in the generator impedance and pulse width without a significant increase in the generator dimensions, with the energy stored remaining the same.     

A high-power nanosecond pulse generator based on solid-state switches

A high-power nanosecond pulse generator based on a Lewis transformer and ultrafast IGBT-transistors is described. The generator ensures the formation of square pulses at a 50-Ω matched load with a repetition rate of up to 2 kHz. The pulse duration may be freely varied from 20 to 200 ns, and the pulse power may vary from 200 W to 2 MW.     

Operating features of a high-voltage spark gap switch with gas blow normal to the breakdown path in a repetitively pulsed mode

The results of studies of a high-voltage two-electrode spark gap switch (SGS) with forced gas blow at an operation voltage of up to 1.2 MV are presented. An SGS filled with nitrogen as the working gas at a pressure of up to 16 atm operated as the high-voltage switch of a high-current nanosecond electron accelerator. The gas flow was directed normally to the breakdown path. The SGS switched a 50-Ω forming line with an electrical length of 10 ns to a matched load. The voltage rise time across the electrodes before breakdown was ～25µs. A stable repetitively pulsed mode is realized at operating voltages of 100–680 kV and pulse repetition rates of up to 270 Hz with a standard deviation of the pulse breakdown voltage of ≤1%. The physical mechanisms that determine unstable operation of the device during self-breakdown are analyzed.     

A Pulsed Low-Hardness X-Ray Source For Radiography in Explosive Experiments

A simple X-ray unit with an effective radiation energy of 50 keV and a pulse FWHM duration of 25 ns is described. The unit is designed on the basis of a mass-produced high-voltage nanosecond generator synchronized with a 10-ns accuracy. The problems of protecting the unit's radiation head and film cassette under conditions of explosive experiments are considered. The radiography results for a cumulative metallic copper jet 2 mm in diameter moving at a velocity of several kilometers per second, and for the deformation of aluminum tubes 25 and 32 mm in diameter with 4- and 8-mm thick walls, respectively, upon the explosion of a few tens of grams of an HE charge, are presented.