[en] Experimental research of 'order-order' kinetics in binary intermetallics showing highly stable superstructures revealed that specific features of 'order-order' relaxations are attributed to the type of superstructure. Corresponding simulation studies elucidated specific atomistic mechanisms of the processes. It has been shown that two time scales revealed experimentally in 'order-order' relaxations in L1₂ and L1₀-ordered systems follow from an interplay between ordering/disordering and the easy diffusion of antisites within one sublattice. In triple-defect B2-ordered intermetallics, strict correlation between ordering/disordering and vacancy elimination/formation dramatically slows down the process despite very high vacancy concentration

[en] Results of investigation of ion emission from two plasma-focus systems PF-100 and PF-20 have been presented. Measurements were carried out by means of three different methods: a time-of-flight, a magnetic spectrometer and a pinhole one. The total deuteron number and the energetic distribution are determined and images of the region of deuteron emitting plasma are obtained. The influence of the gas pressure in the chamber as well as the influence of the external, axial magnetic field upon ion emission are defined. (orig.)

[en] The results of spectral examination in soft X radiation range are presented. The plasma generated in the plasma focus device of energy 12,5 kJ was investigated by means of E-580 spectrograph. The main plasma parameters are estimated on the ground of the obtained spectrum. (author)

[en] A fast photographic camera with an electro-optical image converter has been built for investigating short-duration physical processes. The camera can operate as a frame camera (exposure time-10ns) or as a streak camera (maximum time resolution of about 0.1 ns). This camera has been used to study the plasma dynamics in the F-20 plasma focus device. In virtue of the results obtained, a series of important effects was observed that has been inaccessible to a detailed study before. (author)

[en] Particle acceleration was investigated experimentally in the plasma focus devices PF-20 and PF-150. The total number of fast deuterons was determined by the carbon target activation method. Prompt neutrons from a lithium target were recorded with a scintillation counter. The energy spectra of deuterons in a single shot were analysed using a Thomson analyser. For the lower part of the ion spectra, an ion collector and the time-of-flight method were used. Stereoscopic images of the fast ion source were obtained by a set of 5 pinhole cameras with dielectric track detector plates. Deuterons of an energy of up to 5 MeV were observed; most high-energy ions were emitted from hot spots. The fast electron component up to 1 MeV was analysed with a magnetic spectrometer. (J.U.). 11 figs

[en] The macroscopic plasma parameters were measured in the final phase of plasma-focus discharge. The visible spectra of plasma produced in the PF-20, 12.5 kJ, 35 kV Mather type plasma-focus device was detected. Preliminary data of electron density and temperature are presented. The data can verify some assumptions on ionization and heating processes of theoretical models of plasma-focus phenomena. A 'fiber'-like structure was observed, which has not yet have a theoretical explanation. (D.Gy.)

[en] A development of the polarimeter system for measuring the azimuthal magnetic field in the plasma focus (PF) device is presented. Measurements were carried out on the PF-360 device by means of the Faraday rotation (FR) method. It was concluded that current-driven instability of plasma does not cause enhanced diffusion of the magnetic field to the moment when the MHD m=0 instability of the plasma column is observed. (author)

[en] Both the forming and decay stages of dense pinch in the PF-300 device of energy up to 360 kJ were investigated by means of four-frame shadow photography. A streak camera and standard diagnostics neutron and electrical measurements were applied as well. The characteristic times and velocities in the course of PF phenomenon, the dimensions of plasma sheath and pinch were also measured. The high neutron yield was connected with the thin and homogenous plasma sheath, minimum radius of the pinch about 2.5mm and short duration of the expansion and decay of one. It was also observed a MHD instability of the plasma sheath during its collapse in form-of two distortions. Theoretical investigations confirm such instability may appear. In some cases an anomalous structure of the plasma sheath was observed, when it was delaminated. One may conclude it was due to non-classical development of the MHD instability. Besides, a very low neutron yield was registered in such discharges. The streak camera photos made perpendicular to symmetry axis showed two luminous areas in visible range. The first one appeared in the moment of maximum compression, and its duration was only 30 ns when the neutron yield was high. It was observed the shorter time interval between the two luminosities the higher neutron yield. Recently detail studies of the sheath and pinch structure are carried out with an interferometry and Faraday rotation measuring

[en] In this paper we describe some recent results of complex investigations of PF-150 plasma-focus device /E/sub o/ =60 kJ, V=30 k=, P/sub o/ = 3-9 Torr D₂/. The plasma column evolution and both the integral and temporal neutron emission have been studied by means of multiframe interferometry, visible and X-ray speed cameras and neutron probes. Some other diagnostic methods have been used as well. We show the structure and the velocity of plasma sheath are reproducible in the radial implosion stage of plasma-focus phenomenon. We observe the essential differences by shot to shot during both the radial expansion and disintegration of plasma column. This processes are exactly connected with the onset of neutron pulse and the total neutron yield, as we show. The shape and the space structure of the plasma during the neutron emission time interval allow to devine and to verify some concepts of neutron production models. It seems the only local compression of deuterons in small areas may explain so high neutron yields and spectra

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