A High-Voltage Pulse Generator with Inductive Energy Storage and Thyratron

A high-voltage pulse generator with an inductive energy storage is described. Its operation is based on the current interruption by a thyratron. It was shown that a T2-500/20 thyratron is capable of reliably interrupting the current with an amplitude of 800–850 A in an inductive energy storage, forming from a low-voltage (0.5–2 kV) power source voltage pulses with an amplitude of up to 90 kV and leading edge duration of 200–250 ns at the load.     

A gigawatt generator with an inductive energy storage discharge

A design of high-current nanosecond generators with discharge of an inductive energy storage into a 15 Ω resistive load and test data are presented. Parameters of the opening switch made as an electrical explosive current interrupter are optimized. When the voltage applied to the inductive energy storage is 50 kV, the amplitude of the load voltage is 500 kV, and the half-height pulse duration is 250 ns with a pulse power up to 20 GW.     

A current source with an inductive energy storage for measuring pulse impedances of grounding connections

A pulse generator with an inductive energy storage for measuring pulse impedances of grounding connections is developed. The generator produces current pulses with a rise time of 200–300 ns and an amplitude of up to 8 A. In contrast to the capacitive storage sources, it is fully controllable, allows one to adjust the amplitude, and ensures a constant current-pulse shape regardless of the load parameters. The different operation modes of the source are described. The experimental load-current waveforms are presented.     

Linear induction accelerators made from pulse-line cavities with external pulse injection

Two types of linear induction accelerator have been reported previously. In one, unidirectional voltage pulses are generated outside the accelerator and injected into the accelerator cavity modules, which contain ferromagnetic material to reduce energy losses in the form of currents induced, in parallel with the beam, in the cavity structure. In the other type, the accelerator cavity modules are themselves pulse-forming lines with energy storage and switches; parallel current losses are made zero by the use of circuits that generate bidirectional acceleration waveforms with a zero voltage-time integral. In a third type of design described here, the cavities are externally driven, and 100% efficient coupling of energy to the beam is obtained by designing the external pulse generators to produce bidirectional voltage waveforms with zero voltage-time integral. A design for such a pulse generator is described that is itself one hundred percent efficient and which is well suited to existing pulse power techniques. Two accelerator cavity designs are described that can couple the pulse from such a generator to the beam; one of these designs provides voltage doubling. Comparison is made between the accelerating gradients that can be obtained with this and the preceding types of induction accelerator.     

A superconducting magnetic-energy storage system as a source of high-power current pulses with constant amplitude

A facility is described that allows generation of long current pulses with a virtually constant amplitude by a superconducting inductive (magnetic) energy storage with a 5-MJ energy content. The design of this facility ensures the possibility of changing the parameters of an output current pulse by varying the inductances of the magnetic-system’s sections and their electromagnet coupling. This approach allows not only the stabilization of the current pulse but also a severalfold increase in the initial current value. The electric insulation of the storage’s coil can withstand a voltage higher than 200 kV, and a special system of multielectrode current leads can transfer a power of up to 250 MW at a 1.3-kA current from the cold zone (4.2 K) into the warm (300 K) zone almost without energy losses. The current can be increased to 10 kA by changing the connection of the facility’s sections. The facility has been tested in six full-scale experiments and is ready for further tests as a component of electrophysical facilities of various purposes.     

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 pulsed generator of X-ray bremsstrahlung with a high peak exposure rate

A new pulsed generator of X-ray bremsstrahlung based on an inductive energy storage and a plasma opening switch is described. The radiation parameters are as follows: the peak exposure rate is as high as 5 × 10⁹ R/s, and the dose is as high as 800 R.     

A Method for Automatic Experimental Data Processing Based on a Wavelet Transform

A method for experimental data processing based on a discrete wavelet transform is described. The algorithm developed, which allows a highly reliable determination of the signal parameters, was used to automatically process signals taken from an inductive monitor during measurements of the carbon ion beam current in the ITEP-TWAC accelerator (Tera Watt Accumulator). As a result of processing several thousands of records, it was established that the algorithm developed makes it possible to adequately determine the parameters of the analyzed signals.     

Magnetic cummulation generators applied for rapid charging of forming lines

We describe an off-line nanosecond charging device for a short forming line; the device has been created on the basis of an inductive energy storage unit. Energy storage is carried out by the current of an explosive magnetic cumulation generator, and the energy output to the load, by means of an electroexplosive current interrupter. The use of a two-stage, instead of a one-stage, magnetic cumulation generator, consisting of a preamplifier and a dynamic transformer, and two smaller-size generators with sequential connection of secondary windings of dynamic transformers, one of which is connected to the inductive storage unit, and the other, to the current interrupter—has made it possible to substantially increase the line charge voltage. As a result, within a time on the order of 100 ns, it was possible to charge a forming line with an electric length of 5 ns to a voltage of ≥1 MV.     

Compact inductive energy storage pulse power system

An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and opening switch power conditioning techniques with high energy density capacitors as the primary energy store. The energy stored in the capacitor bank is transferred to an air cored storage inductor in 5.5 μs through wire fuses. By optimizing the exploding wire parameters, a compact, robust, high voltage pulse power system, capable of generating reproducibly 240 kV, is developed. This paper presents the full details of the system along with the experimental data.     

A Pseudospark Gap in the Inductive-Energy-Storage Circuit

A pseudospark gap is described that is capable of interrupting a current of up to 1 kA and shaping voltage pulses with an amplitude of up to 110 kV and rise time of 100 ns. Analytical expressions for calculating the energy released in the device at the switching-off stage and the efficiency of the generator with an inductive energy storage system are obtained. The characteristics of the pseudospark gap and of a similar-design thyratron connected in the same circuit are compared. It is found that the turn-off time of the pseudospark gap is shorter than that of the thyratron by a factor of 2.5.     

A high-current subnanosecond electron accelerator with a gas-filled former

A subnanosecond electron accelerator prototype based on the ARSA small-size accelerator with a gas-filled former (nitrogen ~4 MPa) has been developed and studied. The operation principle of the former involves charging of a short storage line and its discharge to a stepped line with an accelerating tube that generates electrons. The recorded electron-beam current pulse length was t_0.5 = 0.3 ns, the current amplitude was at least 1.5 kA, and the maximum electron energy was ~850 keV.     

An Injector for a Multibeam Proton Accelerator

Proton acceleration experiments in a 19-channel accelerator with alternating phase focusing are described. An ion source with a multipolar magnetic field that allows charged particle beams with a small phase volume and a high phase current density to be obtained at the injector output has been developed and tested. A beam with a current >40 mA is accelerated in the experimental multibeam proton accelerator for an energy of 530 keV with this ion source.     

A multi-pulse mode of operation of a magnetocumulative generator

Experimental results of generating a nanosecond high-current pulse burst by a multiwinding dynamic transformer, which is based on the principle of recuperation of the energy stored in the single primary winding, and the method of the sequential magnetic-flux trapping by several secondary windings are described. The inductive energy storage with an opening switch is used to sharpen current pulses of the generator. Six small electric capacitors are in turn charged up to ∼300 kV for ∼100 ns with a time interval of 10 μs.     

三相六电平电流型逆变器仿真与实验研究

分析了三相六电平逆变器的工作原理,给出了开关组合序列,并研究了阻容性负载时的逆变器的输出电流波形、均流电感电流波形。最终的仿真与实验结果验证了理论分析。     

ILU-14 industrial electron linear accelerator with a modular structure

A new high-power (up to 100 kW) industrial electron linear accelerator ILU-14 for energies of 7.5–10.0 MeV has been developed by the Budker Institute of Nuclear Physics. The operating frequency of the accelerator is 176 MHz, and the total efficiency is 26%. Owing to the modular structure of the accelerator, the electron energy and the beam power can be varied within certain limits by changing the modular arrangement. A 5-MeV prototype of this accelerator has been produced and successfully tested. Its design parameters verified in the experiments are as follows: the beam current averaged over the RF period is 600 mA, the beam pulse power is 2.5 MW, and the electron efficiency of the accelerating structure is 68%. By applying an additional RF voltage to the electron gun cathode-grid gap, a 96% transmittance of the beam current has been attained at a minor beam energy spread. The prototype of the ILU-14 accelerator can be used as an accelerator with a beam power of 50 kW.     

Measuring the mechanical recoil impulse of a polymeric target upon impact of a high power electron beam

A method for measuring the mechanical recoil impulse of a target produced by the relativistic electron beam of the Calamary accelerator is described. A detector based on a piezoelectric sensor is used in measurements. Results of measurements are presented for the mechanical recoil impulse produced by the relativistic electron beam with an energy as high as 300 keV, a current of up to 30 kA, and a duration of ~100 ns that is incident on an epoxy target. The energy flux density on the target surface is varied in the range of 1–10 GW/cm². The maximum measured impulse value is 0.32 N · s at an energy flux density of 10 GW/cm² (an energy fluence of 810 J/cm2).     

Investigation of a capillary discharge in xenon on the SIGNAL accelerator

Investigations of an electric discharge in a capillary filled with preliminarily ionized xenon are currently performed on the SIGNAL accelerator. The discharge current is 20–50 kA, and the current rise time is 20–50 ns. The design of the accelerator is described and the results of studies of the capillary-emitted radiation performed with a vacuum X-ray diode and frame X-ray streak camera are presented. The total yield of X rays in the energy range 50–120 eV is ～(30–40) mJ/sr, and the maximum radiation power is 0.4–0.5 MW/sr.     

An Inductive Pulse Power-Amplifying Stage with Electric-Explosion Circuit Switching

An inductive power-amplifier stage based on a two-coil assembly and two electrically exploded conductors used as circuit breakers is described. Owing to the magnetic flux conservation, the interruption of the current in the first of the storage coils causes an increase of the current in the second coil, which results in a rapid thermal burst of the second electrically exploded conductor. As a result, the load-current rise-time is 20 times less than the charging-current rise time and the amplitude of the current increases.