[en] Theoretical analysis of dependence of light flux intensity on scintillator thickness is carried out. It has allowed to optimize the choice of thickness and type of scintillation material for detection of x-ray and gamma radiation within 0.01-10000 MeV energy range. Optimal thickness for CsI(Tl), CdWO₄, Bi₄GeO₁₂ and ZnSe scintillators at photon detection within the enrgy given range are determined. ZnSe crystals tured to be the optimal ones to detect radiation within 0.3-0.5 MeV energy range. It is advisable to use scintillators with high atomic number that is Cd₄ and Bi₄GeO₁₂ within the range of higher energy

[en] A theoretical analysis of luminous-flux intensity as a function of crystal thickness is performed for various photon energies, and the optimal thicknesses of CsI(Tl), CdWO₄, Bi₄Ge₃O₁₂, and ZnSe crystals are determined for registration of photons with energies of from a few kiloelectron volts to hundreds of megaelectron volts

[en] Spectral-kinetic characteristics of X-ray luminescence, parameters of thermostimulated luminescence are investigated and optical properties of radiative recombination centers and intermediate capture in isovalently activized crystals of zinc selenide are determined. It is shown that for scintillators on the basis of ZnSe-ZnTe compound dependning on stoichiometry (or the presence of other isovalent impurities) the intensity, spectral composition and luminescence kinetics can be largely determined by the presence of electron and hole traps with the depth of 0.13-0.75 eV; in other cases luminescence parameters mainly depend on the concentration and time of recharging of one type intrinsic defects in zinc selenide lattice, which play the role of radiative recombination centres. The role of tellurium as isovalent activator in the formation of specific optical properties of ZnSe:Te crystals is determined. 6 refs.1 tab

[en] Thermodynamic analysis of annealing processes of charge for scintillation crystals ZnSe doped with tellurium was used. The optimal variant of medium (mixture of hydrogen selenide and hydrogen) and temperature conditions (773 K) was chosen. 11 refs., 1 fig., 2 tabs

[en] Radioluminescence of cadmium sulfide single crystals doped with tellurium and mercury and of zinc sulfide and selenide single crystals doped with tellurium is examined. Single crystals have been grown from a melt under pressure. Radioluminescence is excited by X-ray at 8-10 keV up to 1 MeV. The radioluminescence spectra are studied in the range of 90-300 K. The effect of the impurity concentration on the radiation intensity is analyzed. The data obtained allow one to make a supposition on a mechanism of radioluminescence. Most probable mechanism is radiative recombination on the centres which are inherent defects of the lattice. An isovalence impurity is not so important in this case. It helps the formation of inherent defects of the lattice and results in their freezing with increasing temperature. A conclusion is made that efficiency of radioluminescence of A²B⁶ compounds with an isovalence impurity is not second to that of already well-known scintillators

[en] Experimental data attest that the characteristics of ZbSe(tE) base scintillators do not practically change under the effect of gamma radiation dose up to 10 Mrad and neutron fluence up to 10¹⁵ cv^-2. It is noted that these indicators are several times higher that the radiation resistance level of scintillators based on alkali-haloid crystals. The application of the notion instability zone has allowed the authors to analyse quantitatively the mechanism of radiation defect formation and conditions of crystal stability improvement. It is shown that alloying of ZnSe crystals with isovalent Te results in a radical distortion of the lattice due to thye displacement of metal atom from the centre of tetrahedron and is accompanied with the concentration of vacancies in cation sublattice C_zu^v=2x10^-5 which is several times higher than the equilibrium concentration of V_zu in nonalloyed ZnSe crystals. These factors facilitate the improvement of radiation stability of ZnSe(Te) crystals

[en] The advantages of using scintillator-photo diode systems for radiation detection as compared with traditional and widely used scintillator-photoelectron multiplier systems are discussed The properties of scintillators and photodetectors which are used or can be used in the scintillator-photodiode system are analyzed, their connection with characteristics of the whole system is considered. The above systems are characterized by low power consumed, smaller dimensions and weight, increased reliability and stabilty, liniarity of exit characteristics in the wide dynamic ranges of intensity and radiation energy. The most widely spread CsI(Tl)-silicon photodiode combination has the resolution < or approximately 10% and fast-response up to 10^-9 s when registering the spectra of nuclear particles with the radiation energy > 5 MeV. In the clinic dosimetry such system provides 100 times higher dose sensitivity than dosimeters with semiconductor radiation detectors. The conclusion is made that the systems studied have considerable reserves for improving such characteristics as sensitivity, fast-response, level of output noises. The use of these reserves, mainly due to the development of low-noise photodiodes and highly efficient scintillators with well agreed optical characteristics will allow to expand the range of applying the combined detectors with semiconductor photodetectors

[en] To improve the characteristics of the scintillator-photodiode system optical characteristics of scintillators and semiconductor photoreceivers are investigated. The estimation of spectral characteristics matching has been performed analyzing the type of emission spectra. Scintillators on the base of cadmium, sulphides, zinc and zinc selenides with emission maxima in the region of 460, 640, 670, 990 nm as well as the scintillator CsJ(Tl) with emission maximum in the region of 570 nm have been investigated. As a photoreceiver various silicon photodiodes as well as the photodiode on the base of cadmium sulphide and the FEU-79 photomultiplier have been used. Spectral radiation characteristics have been measured by means of a spectrodiffractometer. It is shown that the semiconductor scintillators on the base of compounds of the A₂B₆ type match with photodiodes better than the scintillator CsI(Tl) usually employed in the scitillator-photodiode system. An additional semiconductor scintillators advantage is their non hydroscopicity. It is pointed out that the photodiode on the CdS base possesses high sensitivity and is perspective in its usage

[en] A theoretical model of multi-energy radiography (MER) is proposed. It is shown that, as distinct from the conventional radiography, MER allows identification of organic substances and control of their chemical composition. Broad prospects are noted for MER application, specifically, for detection of prohibited substances (explosives, drugs, etc.) during customs and anti-terrorist safety inspection

[en] Results of measuring time and spectrometric performances of CdS(Te) scintillation crystals grown from the melt under pressure are presented. A possibility of using detectors on the basis of cadmium sulfide for spectrometry of ionizing radiations at 300 K is disclosed. Energy resolution of the best samples makes up 21% by the line of sup(137)Cs γ-radiation at 662 keV