Beryllium nanoparticles are generated upon ablation of a beryllium target in water by a copper vapour laser. The average size of single crystalline nanoparticles is 12 nm. Ablation of a beryllium target in aqueous solutions of uranyl chloride leads to a significant (up to 50 %) decrease in the gamma activity of radionuclides of the uranium-238 and uranium-235 series. Data on the recovery of the gamma activity of these nuclides to new steady-state values after laser irradiation are obtained. The possibility of application of copper vapour lasers for radioactive waste deactivation is discussed.
A method is proposed for local crystallization of glasses under laser irradiation. This method makes it possible to nucleate and grow microcrystals with a size distribution similar to a monodisperse distribution for several fractions of a second in any glass region chosen in advance. It is demonstrated using glasses in the La 2 O 3 -B 2 O 3 -GeO 2 system as an example that the crystallization of the stillwellite-like phase LaBGeO 5 with the composition close to the composition of the initial glass is observed in the glass under irradiation with the copper vapor laser operating in the high-speed pulse modulation mode. Strips (up to ~300 µ m) produced at a specified depth from the glass surface contain extended regions consisting of uniformly distributed crystals, which have almost identical sizes, exhibit a pronounced faceting, and are identified using X-ray diffraction. The size and the number of crystals can be changed over a wide range by varying laser treatment conditions. This opens up the way to the design of new glass-ceramic materials in which the location of the crystalline phase in the glass bulk is controlled by a developer.
On the created stand, in laboratory conditions, various phases of discharge development characteristic of lightning were simulated using an electric spark in a long air gap. With the help of special radio equipment, the radio emission of a long electric spark was investigated. It is found that at the stages of development of a spark discharge, radio emission is recorded in a long interval up to at least a frequency of 1.4 GHz. Data on radio emission in this range are of great practical importance for such areas as radio communication (during thunderstorm activity), radar, lightning direction finding. Keywords: Long electric spark, lightning discharge, radio emission, streamer discharge, lead discharge, radio communication.
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