A compact subnanosecond high-voltage bipolar pulse generator with spark gaps

Two modifications of the compact subnanosecond high-voltage bipolar pulse generator with an active unit based on a high-impedance charging line, forming line, and two uncontrolled nitrogen spark gaps without gas purging are studied. In both cases, the forming lines are charged with compression of the energies of incident pulses with a ∼160-kV amplitude, a ∼4-ns duration, and a ∼1.5-ns leading edge. The difference of operation modes of the circuits and their efficiency are specified by a point of connecting the load. In conditions of nanosecond prebreakdown overvoltage at a 100-Hz repetition rate, the spark gaps were energized with a relative scatter of ±(100–170) ps, thus specifying the stability of the shape of output bipolar pulses with a voltage difference up to 250 kV.     

A compact semiconductor opening swith-based generator with a 300-kV output voltage and up to 2-kHz pulse repetition rate

A compact generator with a semiconductor opening switch (SOS-diode) shaping across resistive load pulses with an amplitude of up to 300 kV, duration of 30–50 ns, and a 300-Hz pulse repetition under uninterrupted operation and up to 2 kHz in a 30-s burst mode is described. The generator contains a thyristor charging device, magnetic compressor, and inductive storage with a semiconductor opening swith based on SOS-diodes. The average output power at a maximum pulse repetition rate and a 250kV-voltage is 16 kW. The overall dimensions of the generator are 0.85×0.65×0.42 m, the weight is about 115 kg.     

Multiple-circuit pulse generator for high repetition rate rare gas halide lasers

A multiple-circuit high pulse repetition frequency (PRF) pulse generator for the pumping of rare gas halide lasers is reported. With this multiple-circuit design, high PRF can be achieved by the use of existing low PRF thyratron switches and capacitors. A two-circuit pulse generator was constructed, and its performance is described. By means of this pulse generator and a blowdown-type fast transverse-flow system, high PRF laser action in XeF was obtained, typically, 6 mJ/pulse at 1 kHz or 6 W average power. High PRF laser action in N(2) was also observed.     

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 low-impedance high-voltage bipolar pulse former

The results on the formation of bipolar pulses with amplitudes of up to 100 kV, a duration of 2 ns, and a pulse repetition rate of 100 Hz across a 12.5-Ω load are presented. Lines with a characteristic impedance of 6.25 Ω were switched using multichannel ring switches with 70-mm-diameter electrodes in a nitrogen medium at a pressure of 40–60 atm. At a pressure of 40 atm, the rms deviation of the operation time of the sharpening switch reaches 40 ps at a voltage-pulse rise rate of 7 × 10¹³ V/s at the electrodes. As the pressure increases, the stability of the output bipolar pulses deteriorates; this is probably associated with a disturbance of the multichannel-switching mode in the sharpening switch. The performed simulation of the pulse-former operation showed that the energy loss in the switches reaches 40% of the stored energy in the output line of the Sinus-160 generator.     

A compact nanosecond pulse generator

A compact high-current pulse generator with the amplitude of the load current up to 140 kA and rise time below 200 ns is designed. The basic element of the pulse generator design is the HCEIcap 100–0.2 capacitor switch assembly. The capacitance value of the capacitor switch assembly is 200 nF, the charging voltage is 100 kV, the energy storage is 1000 J, and the full inductance value is 20 nH. The sizes of the active part of the capacitor are 80-mm inner diameter ×160-mm outer diameter ×160 mm. A multigap spark-gap is used as a switch. The rise rate of the current through the load (X-pinch, 2 molybdenum wires with a 25-μm diameter) is 1.3 kA/ns, and the soft X-ray pulse duration is 2.0–3.5 ns.     

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.     

Investigation of the operation of a bipolar transistor in the mode of a nanosecond opening switch

The results of an experimental study of the operating mode of a high-voltage bipolar transistor are presented. This mode provides an abrupt (nanosecond-duration) recovery of the blocking ability of the collector in a common-base circuit and the formation of high-voltage pulses with a nanosecond rise time.     

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.     

A high-voltage nanosecond pulse generator based on a barrier discharge

One of the specific features of the barrier electric discharge is the short duration of microdischarge processes that last about tens of nanoseconds. A high-voltage nanosecond pulse generator based on a barrier electric discharge is presented. A voltage of tens of kilovolts is usually applied to electrodes of the discharge cell. The peak values of the current pulse may be very high (from a few amperes to several tens of amperes). The presented high-voltage nanosecond pulse generator, having a sufficiently simple design, ensures quite good pulse repetition stability, and, when necessary, allows one to easily tune characteristics of pulses and their repetition rates by changing the geometrical, electrical, and physical-chemical parameters of the setup.     

Nanosecond square high voltage pulse generator for electro-optic switch

A scalable square high voltage pulse generator, which has the properties of fast rise time, fast fall time, powerful driving capability, and long lifetime, is presented in this paper by utilizing solid state circuitry. A totem-pole topology is designed to supply a powerful driving capability for the electro-optic (EO) crystal which is of capacitive load. Power MOSFETs are configured in series to sustain high voltage, and proper driving circuits are introduced for the specific MOSFETs configurations. A 3000 V pulse generator with ~49.04 ns rise time and ~10.40 ns fall time of the output waveform is presented. This kind of generator is desirable for electro-optic switch. However, it is not specific to EO switch and may have broad applications where high voltage fast switching is required.     

A compact high-voltage nanosecond marx generator based on air-field dischargers

Results of the development and study of a 14-stage air high-voltage pulse generator with an output voltage of up to 250 kV, a current rise time of 10 ns, and blow capacitance of 400 pF are presented. The design and the schematic circuit diagram of the generator are described.     

A compact, low jitter, nanosecond rise time, high voltage pulse generator with variable amplitude

In this paper, a compact, low jitter, nanosecond rise time, command triggered, high peak power, gas-switch pulse generator system is developed for high energy physics experiment. The main components of the system are a high voltage capacitor, the spark gap switch and R = 50 Ω load resistance built into a structure to obtain a fast high power pulse. The pulse drive unit, comprised of a vacuum planar triode and a stack of avalanche transistors, is command triggered by a single or multiple TTL (transistor-transistor logic) level pulses generated by a trigger pulse control unit implemented using the 555 timer circuit. The control unit also accepts user input TTL trigger signal. The vacuum planar triode in the pulse driving unit that close the first stage switches is applied to drive the spark gap reducing jitter. By adjusting the charge voltage of a high voltage capacitor charging power supply, the pulse amplitude varies from 5 kV to 10 kV, with a rise time of <3 ns and the maximum peak current up to 200 A (into 50 Ω). The jitter of the pulse generator system is less than 1 ns. The maximum pulse repetition rate is set at 10 Hz that limited only by the gas-switch and available capacitor recovery time.     

Generators of high-voltage pulses with a repetition rate of 50000 pulses per second

We study the schematic and mechanical features of frequency (∼50000 pulses/s) generators of high-voltage (up to 10 kV) pulses of the microsecond range. We analyze (with the purpose of decreasing energy consumed from the power network) the energy transfer process from a low-voltage discharge circuit (with insulated-gate bipolar transistors as commutators) by means of a step-up pulse transformer to the load. We implement the design of a generator with pulse front sharpening in the load (into a reactor with pulsed corona discharge) using a multigap air discharger. The maximum achieved pulse repetition rate with a sharpened front was ∼27 000 pulses/s and a voltage of ∼3 kV.     

A semiconductor opening switch-based quasi-rectangualr pulse generator operating into a low-impedance load

A generator with a semiconductor opening switch (SOS-diode) operating into a low-impedance load of 4–5 Ω is studied. The amplitude of quasi-rectangular pulses is 50 kV at a half-height duration of 100 ns. The energy is applied from an intermediate storage via a spark gap to the output generator stage. The output pulse is formed by solid-state components.     

基于 CPLD的双通道高压脉冲信号源

针对声波测井压电陶瓷换能器容性大的负载特性,采用单片机和CPLD相结合的方式设计了一种输出幅度高、驱动电流大、脉冲宽度可调的双通道高压脉冲信号源。系统利用C8051F350单片机及PWM控制芯片MM33060A,并结合自耦变压器反激式升压电路将12 V直流供电电压抬升至300 V。采用CPLD产生精确的频率可控的300 V脉冲电压,利用脉冲变压器进一步提升电压,得到了上千伏的高压激励脉冲。实验结果标明,设计的信号源在激励压电陶瓷换能器时,负载上得到了比较理想的波形,波形上升沿陡峭,无拖尾及振荡现象,满足实际应用需求。     

A high-voltage pulse transformer with a modular ferrite core

A high ratio (winding ratio of 1:80) pulse transformer with a modular ferrite core was developed for a repetitive resonant charging system. The magnetic core is constructed from 68 small blocks of ferrites, glued together by epoxy resin. This allows a high degree of freedom in choosing core shape and size. Critical issues related to this modular design are the size tolerance of the individual ferrite blocks, the unavoidable air gap between the blocks, and the saturation of the core. To evaluate the swing of the flux density inside the core during the charging process, an equivalent circuit model was introduced. It was found that when a transformer is used in a resonant charging circuit, the minimal required volume of the magnetic material to keep the core unsaturated depends on the coupling coefficient of the transformer and is independent of the number of turns of the primary winding. Along the flux path, 17 small air gaps are present due to the inevitable joints between the ferrite blocks. The total air gap distance is about 0.67 mm. The primary and secondary windings have 16 turns and 1280 turns, respectively, and the actually obtained ratio is about 1:75.4. A coupling coefficient of 99.6% was obtained. Experimental results are in good agreement with the model, and the modular ferrite core works well. Using this transformer, the high-voltage capacitors can be charged up to more than 70 kV from a low-voltage capacitor with an initial charging voltage of about 965 V. With 26.9 J energy transfer, the increased flux density inside the core was about 0.23 T, and the core remains unsaturated. The energy transfer efficiency from the primary to the secondary was around 92%.     

高重频短脉冲输出的增益开关型Nd^3＋：YVO4微片激光器

以直流偏置叠加脉冲电流驱动的半导体激光器(LD)作为抽运源,端面抽运Nd3+∶YVO4平-平腔微片激光器.利用增益开关技术,调节LD驱动电流的幅值、脉宽可改变输出激光的脉宽,改变LD驱动电流的重复频率可改变输出激光的重复频率,实现了单模稳定、可控高重复频率的小型、全固化短脉冲激光器,可作为理想的脉冲激光种子光源,应用于激光测距、激光雷达等领域.     

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.