This paper reports on the creation of a THL-100 multi-terawatt hybrid laser system based on a Start-480M titaniumsapphire starting complex and photochemical XeF(C-A) amplifier with a 25-cm aperture. The complex produces 50-fs radiation pulses of energy up to 5 mJ at a second harmonic wavelength of 475 nm. The active medium of the amplifier is created in a XeF 2 /N 2 mixture under vacuum-ultraviolet radiation of electron beam-excited xenon. The results of first experiments on femtosecond pulse amplification in the active medium of the XeF(C-A) amplifier are presented to demonstrate that a laser beam peak power of 14 TW has been attained.

The results of the experimental studies of the high-power e-beam accelerator producing six radially convergent electron beams are presented. The studies are aimed to increase the energy of the electron beam transported through the foil into the gas-filled chamber by using the rod-shaped current returns in the diode at small inter-electrode gaps. Installation of these rod current returns shields the periphery regions of the diode from the current field in the central part thus reducing the field at the diode edge. The inter-electrode distance, the shape, and the sizes of the cathodes are chosen by taking into account the magnetic field reduction in the diode. It is shown that in such type of the diode the electrons impact the foil almost normally to its surface, and the electron beams enter the output windows completely. Such type of the diode allows increasing the efficiency of the electron beam energy transfer into the gas by 30%.

In this paper, we give a review of some most powerful pulsed systems developed at the Institute of High Current Electronics (HCEI), Siberian Branch, Russian Academy of Sciences, and describe latest achievements of the teams dealing with these installations. Besides the presented high-power systems, HCEI performs numerous investigations using much less powerful generators. For instance, last year much attention was paying to the research and development of the intense low-energy (<200 kV) high-current electron and ion beam and plasma sources, and their application in the technology [1–3].

High quality lithium borate (LBO) samples cut along (1 0 0), (0 1 0) and (0 0 1) axes were studied by terahertz time-domain spectroscopy (THz TDS) between 0.2-3 THz. It was found that in the direction of crystallographic axis X the optical absorption coefficient is the lowest amongst all known anisotropic nonlinear crystals, and that birefringence is as large as 0.42. Dispersion equations for the entire transparency range of LBO were developed for the first time. Phase matching for down-conversion into the THz range was found to be possible. Phase matching availability, low optical loss in the transparency band, and high optical damage threshold make LBO one of the most promising nonlinear materials for THz generation.

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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.

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