Антропологические аспекты облучения малыми дозами радиации и краткий обзор современной радиоэкологической обстановки в Украине

Человечество сосуществует с радиоактивным излучением на протяжении всей своей истории. Речь идет, безусловно, о так называемых малых дозах облучения. Начиная с ХХ в., к естественным источникам радиоактивного загрязнения добавились еще факторы антропологического происхождения, связанные с научно-технической революцией в сфере использования ядерной энергии. В данной статье авторы хотят обратить внимание на некоторые детали формирования и влияния малых доз радиационного излучения и дать краткий обзор радиационной обстановке в Украине, которая существенно влияет на их характеристики.The mankind coexists with a small dosed irradiation during the whole period of its development. So called small or weak doses of irradiation are meant. Since the XX century the natural sources of radiation have been added by the factors of anthropological origin connected with a technical progress in the nuclear industry. In the present paper the authors are trying to outline some details of the formation and influence of the small dosed irradiation. A short review of a modern radioecological contamination map of Ukraine is also proposed

Additive manufacturing of inorganic scintillator-based particle detectors

Inorganic scintillators are widely used for scientific, industrial and medical applications. The development of 3D printing with inorganic scintillators would allow fast creation of detector prototypes for registration of ionizing radiation, such as alpha and beta, gamma particles in thin layers of active material and soft X-ray radiation. This article reports on the technical work and scientific achievements that aimed at developing a new inorganic scintillation filament to be used for the 3D printing of composite scintillator materials: study and definition of the scintillator composition; development of the methods for the inorganic scintillator filament production and further implementation in the available 3D printing technologies; study of impact of the different 3D printing modes on the material scintillation characteristics. Also, 3D printed scintillators can be used for creation of combined detectors for high-energy physics.Comment: 14 pages, 16 figure

Nonlinear behavior of structural and luminescent properties in Gd(NbxTa1-x)O-4 mixed crystals

International audienceCeramic samples of gadolinium tantalo-niobate mixed crystals were obtained by the solid-state technique. The dependence of luminescence properties on the Nb/Ta ratio in the Gd(NbxTa1-x)O4 system is studied in the 5–450 K temperature range, including thermostimulated luminescence curves in the series of solid solutions. The relation of nonlinear behavior of light output with x variation to non-homogeneous distribution of Nb and Ta in solid solutions is discussed

Engineering of mixed Bi₄(GexSi₁₋x)₃O₁₂ scintillation crystals

A full range of BGSO crystals from BGO to BSO was grown by the Czochralksi method. A set of procedures such as changing of stoichiometry, recrystallization and thermal treatment was applied to improve optical and scintillation parameters of the crystals. The relationships between scintillation yield, energy resolution, decay constants and Si⁴⁺/Ge⁴⁺ ratio in the crystals are discussed with regard to ongoing experiments on high energy physics. Crystal composition with better energy resolution 16.2 % at 662 keV irradiation was obtained

Fast ultradense GdTa1-xNbxO4 scintillator crystals

International audienc

Characterization of mixed Bi4_4(Gex_xSi1−x_{1-x})3_3O12_{12} for crystal calorimetry at future colliders

Bismuth germanate (BGO) is a well known high density scintillating material widely used in many applications such as high energy physics and medical imaging. Bismuth silicate (BSO) features properties similar to BGO in terms of stopping power and Cherenkov photon yield with a lower scintillation light output but faster decay time, thus being more attractive for applications in high-rate environments. Mixed crystals such as Bi$_4$(Ge$_x$Si$_{1-x}$)$_3$O$_{12}$ (BGSO, with varying from 0 to 1) make it possible to optimize decay time and light yield based on the detector needs. A characterization campaign of the optical and scintillation properties of two sets of BGSO mixed crystals with Ge fraction varying from 0 to 100% was performed. A coincidence time resolution (CTR) at 511 keV of 208 ±2 ps FWHM was measured for a 2 × 2 × 3 mm$^3$ pixel with 40% Ge, while the optimum value obtained for the effective decay time is 49.9 ±1.8 ns for a 6 × 6 × 0.7 mm$^3$ plate-shaped sample with 30% Ge. Furthermore the smallest slow decay time component achieved is 101 ±2 ns and is obtained for the plate-shaped sample with 30% Ge, while the largest is 236 ±5 ns for a pure BGO sample with the same geometry. In addition we demonstrated the possibility to efficiently separate the Cherenkov and scintillation light produced in a pure BSO sample. Such a technique could be exploited in a crystal-based dual-readout calorimeter to improve the energy resolution for hadronic showers and jets

Progress in fabrication of long transparent YAG:Ce and YAG:Ce,Mg single crystalline fibers for HEP applications

International audienceA significant enhancement in the light attenuation length in 22 cm long YAG:Ce and YAG:Ce,Mg fibers grown by the micro-pulling-down method has been reported. This progress has been achieved by the introduction of Al excess into the melt, optimization of thermal conditions of crystallization and post growth annealing. Attenuation length clearly correlates with surface roughness of the fibers. Al excess addition over the stoichiometric composition enhances the fiber surface smoothness. An increase in axial thermal gradient and melt pressure in the crucible capillary die improves the crystallization process stability. Mg codoping provides a Ce3+ scintillation decay time decrease down to 80 ns