[en] The first results of direct measurements of the characteristics of dust particles with mass m of greater than 10 to the -9th g by the Foton detector, carried on the VEGA 1 and VEGA 2 space vehicles, are reported. The nature of the changes in the dust flux along the trajectory of the space probe is reported. The mass distribution of the dust particles is also reported. 7 references

[en] Results of the experimental determination of the physical characteristics of a spin-flipper with a prolonged working area are presented. The construction of the working version of the spin-flipper is described. Measurements were performed with a non-monochromatic beam of polarized thermal neutrons with an average wavelength lambda = 1.96 Angstroem and a polarization of about unity. The dependence of the probability of the neutron spin reverse on the site of neutron transmission through the spin-flipper as well as on the current in the coils of the flipper is given. The maximal spin reverse probability averaged over the spectrum (the beam cross section being 0.5 x 22 mm²) was 0.9993 +- 0.0001. The linear dependence of the reverse probability on the wavelength is confirmed up to 4 Angstroem. The working version of the spin-flipper was constructed in the Laboratory of Neutron Physics JINR (Dubna). Experiments were performed in the LNPI (Gatchina, USSR). (orig.)

[en] Full text: The paper reports on investigations performed in Institute of Nuclear Physics regarding the factors of radiation impact at oil extraction in Western Kazakhstan and outlines the most important obstacles that hinder the improvement of radioecological situation in accordance with contemporary requirements on handling radioactive waste and protection of personnel and population. Way to solve these problems are proposed. Safety issues in fuel and energy industry is of primary importance, Particularly in Kazakhstan that is one of gas and oil producing countries. Along with other aspects of safety it is necessary to take into consideration the radiation impact from accumulated from oil extraction 2 million tons of waste that contains radionuclides of radium and lead, including long-lived ones (with half-life of 1600 years). So, there were investigated all current Kazakhstan regulatory documents on radiation safety, national and foreign experience in surveying of contaminated sites, their decontamination, processing and utilization of radioactive waste and there was prepared a new document 'Manual on radio-ecologically safe utilization of waste from oil-and-gas production'. This document regulates the whole cycle of environment protecting measures at waste utilization for the named industry and is aimed on lowering the radiation risks and assurance of radioecological safety both at present and for the future. Beyond considerable funds required for processing and preparation for burying large amount the radwaste materials, utilization of oil tailings is complicated by following main problems. At first, people worldwide pay much more attention to environmental issues including those influencing next generations, what has resulted in sharp (for a hundred times) toughening of the requirements to acceptable levels of radiation impact on population in places adjacent to radwaste disposal sites. At the same time there is no proven reliable technology for burial of waste with long-lived natural radionuclides. Another important aspect of waste utilization for oil industry is that artificial radiation sources at oil extraction are the natural radionuclides, highly dispersed in the nature. The control over keeping in compliance with modern permissible limits for dose from radioactive waste is reduced, thus, to revealing of excess for 10 μSv annually above the natural annual natural background of about 2400 μSv for the excess stipulated by radionuclides of the same isotope composition. Taking into account that the natural background values vary for several times depending on location and living conditions, it becomes clear that the problem can be solved only at a level of an estimation of possible influence and forecasts of probable behavior in the future. Specialists from many countries nowadays try to solve this problem. Considerable progress has been made within the Coordination Project ISAM (1997-2000), coordinated by IAEA. There was developed the methodology of the approach to assessment of impact from near-surface disposal facilities of radioactive waste (FEPs a sheet). Now within the framework of the following IAEA Coordination Project ASAM (2002-2006) the works are in progress on application and improvement of the designed methodology; more than 60 specialists from 30 countries take part in this work. Kazakhstan has to take an active part in this program assure compliance of the industrial activities with the international standards

[en] In this paper a polarizing neutron guide made from 50Co50Fe mirror with an absorbing underlayer is described. The neutron guide design and results of its test on the reactor VVR-M (Leningrad Nuclear Physics Institute, Gatchina) are reported. The flux at the end of the 1.6 x 30 mm² neutron guide was equal to 1.7 x 10⁷ n/cm²s with a reactor power of 16 MW. Polarizations averaged over the spectra of the outgoing beam for narrow and broad incoming collimations were 0.95 and 0.97, respectively. (Auth.)