The results of the development and the main characteristics of a new generation of semiconductor current switches (250 kA/25 kV/70 C) based on assemblies of series-connected reverse switched-on dynistors (RSDs) are presented. The methods for increasing the switched power and increasing the service life and reliability of RSD switches with maintenance of the previously accepted weight and size indicators were studied. The problem was solved by reducing the RSD power loss and increasing the resistance of the contact connections to the effects of high-power current pulses. The switch design was modernized and the silicon structure was optimized; a new technology for low-temperature connections in the silicon–metal system with the use of silver was developed, thus making it possible to double the active contact area and improve the load characteristics and service life of the new switches. The operating and maximum permissible values of the starting and switched currents were determined. The results of the operation of RSD switches in capacitive energy-storage devices of high-power laser devices are presented. Based on the results of life tests, the service life of new devices was assessed.

The results of the development and experience of operation of a modernized charging system of the capacitor bank of the Iskra-5 laser facility are presented. The main performance characteristics of the devices that are included in the charging system are presented. A method for creating the hardware and software for the remote control and monitoring of the parameters of charging devices is described. The serviceability of the charging system during the operation of the facility is evaluated.

An investigation is made of the dynamics and visible-range luminosity of the plasma cloud produced behind the front of a shock wave in air at a pressure of 1 Torr. The shock wave was produced on introducing the radiation of the twelve-channel Iskra-5 laser facility with a total energy of ∼2300 J into a hollow spherical plastic target of mass ∼10-4 g. Experimental data are compared with simulations.

The radiation characteristics of a pulsed discharge xenon lamp are experimentally and theoretically studied. The data on radiation spectra are obtained for various compositions and pressures of working medium, energies and time profiles of excitation pulse, discharge gap configurations, etc. Electron temperature and mean spectroscopic symbol of emitting ions are estimated. It is demonstrated that cw radiation (continuum) results from the photorecombination transitions.

Summary form only given. The high-power UV radiation in spectral range of 200-300 nm is required for a set of applications such as decontamination of water, food etc. As known the tube xenon flash lamp is the simple and efficient source of UV radiation. In this report the results of experimental investigation of high-power tube xenon flash lamps at microsecond duration of discharge are presented. We tested flash lamps with inner diameter from 10 to 20 mm and distance between lamp electrodes from 180 to 930 mm at discharge duration less than 5 mus. It has been obtained that integrated mode of pulse preionization greatly increase the energy and efficiency of lamp radiation in the spectral range of 200 - 300 nm, and increase the lamp lifetime too. We also observed that for external surface of lamp bulb the density of radiation power in the spectral range of 200 - 300 nm was more than 100 kW/cm 2 , and efficiency was not less than 10%.

Summary form only given. Since 2000 year LUCH laser facility has been worked at RFNC-VNIIEF. This facility was designed as prototype of ISKRA-6 128-beams facility that is developing now. Basis of LUCH facility is 4-beams Nd-glass laser with operating aperture 20times20 cm. This laser is included two four-path amplifiers that are pumped by 432 xenon flashlamps. The capacitor bank with near 5MJ stored energy at operating voltage of 24 kV has been constructed to drive amplifiers flashlamps. 18 unified modules are included in the bank. Each single module is discharged to lamp load by semiconductor closing switch based on reverse switched dynistors. Description of module components and bank subsystems such as charging, triggering, control and diagnostic is presented in this report. Also the bank performance during the exploitation is discussed.

Summary form only given. The ISKRA-6 laser is a 128-beam, flashlamp-driven neodymium-glass laser that will produce near 0.6 MJ of light on target. Each of the 128 beams of the ISKRA-6 laser is amplified in two four-pass laser amplifiers. Pumping system of these amplifiers is consisted the 5120 xenon flash lamps that are drove by a power conditioning system. ISKRA-6 power conditioning system (PCS) is based on the capacitor storage bank to deliver approximately 35 k.F to each of 5120 flashlamps. So, PCS will be capable of storing nearly 215 MJ of electrical energy at 24 kV The capacitor bank will include the 256 unified modules. This paper describes the design of module and results of testing of module prototype. It also discusses the components of module including self-healing capacitors, main semiconductor closing switches based on reverse switched dynistors, and other components.

Summary form only given. A new generation of semiconductor closing switches based on reverse switched dynistors (RSD) has been developed to switch high-power current pulses with microsecond duration. In this report the results of theoretical and experimental investigations of RSD at peak current more than 500 kA and pulse duration up to 500 mus (at 0.1 Imax) are observed. The criteria of extreme peak current for switch taking into consideration the longtime performance under pulse-periodical mode are gave. The design and test results for switch under single pulse mode at operating voltage up to 25 kV and peak current up to 300 kA are described. The possibility of using such a switch in the ISKRA-6 capacitor bank is estimated.

The twelve-channel 'Iskra-5' iodine laser facility was updated to enable investigations in the regime of high-power two-pulse target irradiation, when the second pulse is delayed by a time of up to 10 μs relative to the first one and possesses an energy equal to or comparable with the energy of the first pulse.

The conversion of the 'Iskra-5' iodine laser to the regime of fusion target irradiation by second harmonic radiation at 657.5 nm is reported. The laser upgrading enabled obtaining from 12 channels a total second-harmonic energy yield of 2.5 kJ, which corresponds to an output power of 5 TW. The conversion efficiency was equal to ∼50% in experiments with DKDP crystals with an aperture of 35 cm. A series of 12-channel experiments was conducted involving second-harmonic irradiation of microtargets.

The measuring technique is described and time-resolved measurements of the small-signal gain as a function of the pump energy in a disk amplification stage with neodymium phosphate glass active elements in the 'Luch' facility are presented. The distribution of the gain over the amplifier aperture in the horizontal plane is measured.

We describe the operating principle, design and test results for the high-power semiconductor switch which based on the assembly of reverse switched dinistors. This switch has the following operating parameters: (i) operating voltage -25kV, (ii) peak operating current - up to 200kA, (iii) maximum transferred charge - up to 70C. The switch is intended for use by pulse power systems of Nd:glass lasers. The features of switch modes at such banks are discussed.

Performance test results on semiconductor RSD-based switch are presented, which have been obtained at 2MJ test facility in Limeil-Valenton (France). This switch was integrated into a flashlamps drive circuit that corresponded to the power conditioning of main amplifiers for high-power Nd-glass laser of LMJ facility. The switch was loaded by 5 parallel lamp circuits to provide the following operational parameters: 25 kV, 120 kA, 40 Coulombs. It has been shown that this kind of switch may be compatible with preionization pulse mode.

The Z-Beamlet laser at Sandia National Laboratories can perform a full system shot every 3–4 h. This shot rate is limited by thermal aberrations that result from the flashlamp pumped Nd:phosphate amplifier slabs. The lowest order as well as the strongest aberration is of cylindrical shape. Therefore, a single actuator deformable mirror assembly for correction of cylindrical aberration was developed. Mirror performance was modeled using finite element analysis and showed good agreement with derived analytical expressions. Quantitative measurements were performed with an interferometer and thermal lens compensation was achieved in the Z-Beamlet laser system leading to an increased shot rate of one in every 2 h.

Conceptual design of the capacitor bank with about 120 MJ energy storage and 22 kV operational voltage is presented. This capacitor bank will be used to drive the xenon flashlamps for pumping of Nd-glass laser amplifiers which are included in the facility ISKRA-6. Possible components and circuit of the bank module are discussed.