[en] Abstract only

[en] The MIREDO (Muon Induced Rare Event Dynamic Observatory) spectrometer system is primarily developed for the study of cosmic muon induced processes in different materials. Exploration of such interactions can be important for ultra-low background experiments. The system is based on the 100% relative efficiency ultra-low-background HPGe spectrometer. With the addition of two plastic scintillators and a fast-slow coincidence circuit, the coincidence events between the plastic detectors and the HPGe spectrometer have been investigated. First results derived for a CaO powder sample, placed in a Marinelli beaker, are presented and discussed. - Highlights: • The results of the first measurements by the MIREDO facility are presented. • Muon induced radiation production in CaO powder was measured. • In CaO, low-energy continuous radiation and 511 keV gamma ray were produced. • Two neutron-induced lines in Ge have been found

[en] A simple and general approximate method for the determination of the optimal length of cylindrical gamma ray sources is presented. (orig.)

[en] It is well known that radon emanation from soil is a main contributor to radon buildup in houses. Despite this fact, the radon exposure at subsurface workplaces (building foundations, wells etc.) was not examined in the Vojvodina (Yugoslavia) region. A simple method for radon emanation measurement from soil was developed. The method is based on the EPA verified charcoal adsorbing canisters. About 70 measurements are performed yielding ²²²Rn concentrations in the range 1000 Bq/m³. On the basis of these results the radon exposure in holes and subsurface workplaces is estimated to be about 10 mSv/year. (author)

[en] The activity concentration of ¹³⁷Cs, ¹³⁴Cs and ¹⁰⁶Ru in the sediment of the Danube river was measured for a period of 18 months after the Chernobyl accident. From the data fitted with a simple exponential decay function the same value of ''corrected elimination half-life'' T_ec ''approx ='' 240 D was derived for all three radionuclides. (author)

[en] The construction principles and the details of the los-level shielding for semiconductor γ detectors are described. The shield was assembled from steel sheets volume of a m³ and wall thickness of 25 cm. The background measured in the chamber for 200 Ks was free of artificial isotope lines, and in in the energy region 23 - 2700 keV had the integral value 1.060 ± 0.002 counts/s. For the limits for finite size source have been determined. For p_γ = 1 at the energy of 1 MeV the detection limit has the value 0.12 Bq. The additional means of background reduction in the chamber are discussed together with the possible applications of low-level spectroscopy system. (author)

[en] The distribution and elimination of the long-lived fission product ¹³⁷Cs from the Danube ecosystem is discussed. Considering the transport of radionuclides as a general diffusion process, Fick's diffusion law is employed for the description of the observed data of activity concentration in various media (water, sediment, peryphiton and fish). (author) 1 tab., 4 refs

[en] The x-ray energy spectrum from 15 MeV linear accelerator (Siemens Mevatron 77/20) was determined by combination of the attenuation and the photoactivation analysis. X-ray flux of the therapy linac is produced in thick target and filtered through several materials. The theoretical expression for thin target spectrum was corrected for absorption in materials in accelerator head. Low energy part of spectrum was corrected by parameters calculated from attenuation measurements and high energy part of spectrum was determined by photoactivation. (author)

[en] Construction and electronics scheme of gamma-gamma coincidence spectrometer is shown. System performance test is done by ⁶⁰ Co. Detection threshold of system in coincidence mode is calculated. It is shown that for intensive gamma cascades detection threshold below 1 Bq is practically independent of background and can be reached in time interval about 100 s. (author)

[en] The activity concentration of long loved fission and corrosion products and natural radionuclides has been measured in a selected part of the Danube-Tisa-Danube channel system which is not receiving liquid effluents from nuclear power plants. The comparison with the activities measured in the river danube did not show statistically significant differences. The results obtained describe the reference level of radioactivity for the evaluation of the contamination of the system caused by the Chernobyl accident. (author)