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The advent of X-pinch based compact radiographs has significantly expanded the application field of pulsed radiography for diagnostics of fast processes. The key point here is the spatial resolution which these radiographs can provide. The method for determining the size of the soft x-ray (SXR) source based on diffraction imaging of opaque metallic wires and their comparison with the diffraction pattern calculated for an extended source in a given spectral range is presented in the paper. The X-pinch source sizes have been measured taking into account the sensitometric characteristic of the film and the scanner characteristics. By this method it has been shown that the diameter of the X-pinch radiation source for current rise rates in the range 0.7–1.35 kA/ns varies slightly for the spectral range hv >3 keV.

The paper describes a pulsed electron beam accelerator with release of electrons accelerated in a vacuum diode into the atmosphere. The electron energy in the beam is 1 MeV, the average adjustable electron current density is 10–200 А/см2, the average adjustable absorbed dose rate in silicon is 0.2 1011–4 1011 Gy/s, the irradiated area is several square centimeters, and the accelerating voltage pulse duration is adjustable in the range 50–200 ns.

The propagation of a nonlinear magnetic-field diffusion wave generated under the condition of an electrical explosion of flat conductors is investigated in the current skinning mode. Using a MIG terrawatt generator, a number of experiments are performed on electrical explosion of a copper foil, 100 μm in thickness and 5 mm in width, at the current amplitude up to 2.5 MA and its rise rate 100 ns. It is shown that under these conditions a plasma channel is formed by approximately 75-th ns from the current onset. The estimations, made considering the magnetic field enhancement on the foil edges, demonstrate that about 70–80 ns are required for the nonlinear magnetic-field diffusion wave to propagate from the foil edge to its center. A good agreement of the experimental data and the estimates suggested a conclusion that the plasma channel formation is due to the convergence of the nonlinear diffusion wave towards the longitudinal foil axis.

The paper deals with the soft X-ray backlighting based on the X-pinch as a powerful tool for physical studies of fast processes. Proposed are the unique small-size pulsed power generators operating as a low-inductance capacitor bank. These pulse generators provide the X-pinch-based soft X-ray source (hν = 1–10 keV) of micron size at 2–3 ns pulse duration. The small size and weight of pulse generators allow them to be transported to any laboratory for conducting X-ray backlighting of test objects with micron space resolution and nanosecond exposure time. These generators also allow creating synchronized multi-frame radiographic complexes with frame delay variation in a broad range.

Results of investigation of the parameters of the THL-100 hybrid laser system of visible range developed at the IHCE SB RAS in collaboration with the LPI RAS are presented. The laser system consists of the Ti:Sa Start-480M starting complex and the photodissociation XeF(C-A) amplifier with aperture of 24 cm. The starting complex provides 50-fs spectrally limited radiation pulses with energy of the second harmonic (475 nm) up to 20 mJ and 50-ps positively chirped radiation pulses with energy up to 5 mJ. The active medium of the XeF(CA) amplifier is created in the XeF2/N2 mixture upon exposure to VUV radiation of xenon excited by a highpower electron beam. It is demonstrated that record power of 14 TW is attained by amplification of negatively chirped radiation pulse with duration of 1.6 ps in the XeF(C-A) amplifier, and maximum energy of ~3.2 J is realized by amplification of positively chirped radiation pulse.

The first experimental results obtained in visible range using the THL-100 multi-terawatt hybrid laser system after modernization of the starting femtosecond complex and the gas amplifier are reported. The modernization was performed to increase the output beam power at the expense of changing the configuration of the vacuum diode of the electron accelerator used for pumping of the XeF(C-A) amplifier. As a result, the increase of the VUV radiation pumping energy of the active medium of the XeF(C-A) amplifier by 30% is attained. This leads to doubling of the output laser beam energy of the XeF(C-A) amplifier.

Radiography of short-living objects using X-pinch radiation is a new perspective direction in diagnostics developed at the P. N. Lebedev Institute of Physics. High spatial (up to a few tenth of a micrometer) and temporal resolutions (up to 0.1 ns) achieved with the use of the X pinch is extremely interesting to the researches of transient processes and substances in extreme states. The X pinch is produced by two or more crossed wires (with wire diameters up to 30 µm) exploded under the influence of current running through them. Scanning radiation is generated in a dense high-temperature plasma (up to several kiloelectron volts) arising in the region of wire crossing. Among the main requirements on the generator used to create the X pinch are current amplitudes of 150–300 kA and rates of current increase of 1–2 kA/ns. Up to now, these current pulse parameters have been provided only by bulky stationary generators weighing from 300 kg to several tons. In the present paper, a small-size (weighing 70 kg) high-current pulse generator (with current amplitude exceeding 300 kA and pulse rise time of 200 ns) of soft x-ray radiation from high-temperature X-pinch plasma is described.

This paper presents the results of experiments on the generation of pulsed γ radiation of average photon energy ∼1.2 MeV and duration ≤20 ns on the MIG system with a plasma opening switch. Operating modes with a maximum dose downstream of the anode of (1–2)·1013 and 1012 R/s over an area of 2–3 and 100 cm2 are obtained, respectively.

The results of the development and operation of a high-voltage insulation are described. The insulation has been developed for the secondary turn of a high-power pulse transformer. The operating electric field in the insulation on the nanosecond scale is 1.5 MV/cm. The prospects for using this insulation are discussed.

On the basis of general relations, the potential of two approaches to the production of powerful x-rays in the spectral range 7–20 keV is evaluated. The very limited potential of the electron beams of vacuum diodes and thermal radiation of Z-pinch plasma is demonstrated. Some prospects for increasing the power of such radiation by generating high-energy electrons in Z-pinch plasma are investigated.

A high-power transformer-type pulse generator (HPPG) is described. It was designed to generate voltage pulses up to 6 MV and current pulses to 2.5 MA. Its highest pulse power is 2.5 TW. Its comparatively small dimensions and broad pulse-spectrum range combine with low cost to make it a convenient tool for physical research in smaller laboratories.

Experimental study of a plasma-based microsecond current interrupter, with electrodynamic acceleration of the plasma along a coaxial electrode system and expansion at a nozzle, shows the possibility of stable current switching close to its maximum. The possibility of improving the characteristics of this interrupter using a highresistance link between the interrupter and the primary energy store—a capacitor battery—is demonstrated. The voltage and power may be increased by factors of 10 and 4.5, respectively.

A new scheme proposed for the design of high-power, heavy-current nanosecond generators incorporates a VPG [voltage-pulse generator] of low voltage (U≲0.5 MV) for that type of unit, a relatively slow-fed (π≳2.5 µsec) inductive accumulator, an exploding-wire interrupter, fast forming lines, and a transmission line terminating in a vacuum diode. The performance of a subterawatt generator with an initial stored energy of ∼ 100 kJ that was designed and placed in service on the basis of this scheme confirmed the principal assumptions and concepts that it embodies.

The design of a electronic beam pulse generator for industrial applications is described. The parameters of the electron beam are 700 kV, 25 kA, and 1 µsec. The design features of the magnetic circuits and the test bench used to test and inspect them are described.

Experimental and theoretical studies are made of the spatial distribution of a dose of x-radiation from an SNOP-1 accelerator with a diode operating in the electron-beam pinch regime. The Monte Carlo method is used to calculate the spectral distribution of the accelerator radiation, and it is shown that the fraction of ultrahard x-radiation (10–100) keV in the spectrum may reach 40–50%.

Problems in the creation and exploitation of powerful pulsed electrophysical transformers, developed at the Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences, are discussed. The power of the largest installations is 2.5·1012 W (pulsed). The small size, the outside location of the main components requiring maintenance, and the absence of large volumes of transformer oil make the pulsed transformers competitive with pulsed voltage generators.

Preliminary experiments are performed to study a plasma-filled diode terminating a GIT-4 inductive multiplier. It is shown that the admission of a slightly ionized gas (argon) into a vacuum diode can improve the matching of the diode with the generator and increase the yield of x-rays generated by the beam. It is confirmed that the readings of the x-ray detectors depends on the actuation delay time of the value used to regulate the gas concentration in the vacuum gap.