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In this work, the properties of LiF crystals grown using Li of different isotopic compositions are described from the standpoint of their application as fluorescent nuclear track detectors used in measurements in the neutron radiation fields. The crystals were grown using two techniques: the Czochralski method and the micro-pulling-down method. Three isotopic compositions of Li were studied: natural, highly enriched in 6Li, and highly enriched in 7Li. It was found that 6LiF detectors are about six times more sensitive to thermal (low energy) neutrons than natural LiF, which significantly decreases the lower detection limit. 7LiF detectors are insensitive to thermal neutrons, which makes it easier to detect tracks due to other radiation modalities, such as energetic ions or nuclei recoiled in collisions with high-energy neutrons. Besides the response to neutron radiation, no other significant differences in the crystal properties were identified, irrespective of the isotopic composition and crystal growth method employed. [ABSTRACT FROM AUTHOR]

The effect of application of filters, made of different materials and various thickness, is studied by Monte Carlo calculations using MCNP6.2 code. The calculated data were validated by experimental studies (benchmark tests). Experimental results obtained for YAlO3:Mn high-Z TL detectors irradiated to different standard ISO radiation qualities (X-ray series N-40, N-60, N-80, N-100, N-120, N-150 and N-200 as well as isotopic series S-Cs) modified by various metal (copper and aluminum) filters of thickness of 0.5, 0.8 and 1 mm. The experimental results are compared with results of Monte Carlo simulations done for the same 'radiation-attenuator-detector' combinations and geometry. Obtained results show good consistence between the experimental and calculated data that testifies adequacy of the used calculations and their applicability to modeling of modification of an output from the high-Z detectors exposed to photons of various energies. [ABSTRACT FROM AUTHOR]

In this study, the infrared optically stimulated luminescence (IRSL) of single crystals of Ce3+ doped yttrium aluminum garnet (YAG) was investigated for the first time. It was found that infrared stimulation of these crystals, following previous exposure to beta radiation, produces a strong luminescence signal. The highest luminescence efficiency was exhibited by the YAG crystal with 0.1% of Ce. With this crystal, it was possible to measure as low doses as 0.1 mGy. Moreover, IRSL is mainly related to the TL peak at a relatively high temperature of c.a. 175 °C, which leads to quite good stability of the signal in time. These properties create good prospects for potential applications of YAG:Ce in dosimetric radiation measurements [ABSTRACT FROM AUTHOR]

Herein, the development of phosphor‐converted white light‐emitting diodes (pc‐WLED) and scintillators based on the crystals of Ce3+‐doped multicomponent garnets, grown by the micro‐pulling‐down (MPD) method is studied. The combined technique of the "bandgap engineering" and "positioning of Ce3+ 5d‐levels" is applied to the crystals of Gd3−xLuxAl5−yGayO12 (x = 0–1.5 and y = 2–3) mixed garnets for improving their color‐rending properties in pc‐WLEDs application as well as their scintillation figure of merit. The absorption, cathodoluminescence, photoluminescence, photoconversion (PC), and also the scintillation light yield and scintillation decay time measurements under excitation by α‐particles of 239Pu radioisotope are used for the characterization of the crystals. Among all the investigated garnet compounds, the best photoconverting properties are observed in Gd3−1.5Lu0−1.5Al5−yGayO12:Ce crystals at x = 0–1.5 and y = 2.5–3. Meanwhile, the best scintillation characteristics are found in Gd3−xLuxAl5−yGayO12 crystals at x = 0–1.5 and y = 2–2.5. [ABSTRACT FROM AUTHOR]

In the paper, after a brief description of historical development, the theory of thermoluminescence (TL) is presented. Three methods of thermally (TSL), optically (OSL) and radio (RPL) stimulated luminescence are discussed and compared. A wide range of applications of TL detectors in individual and environmental dosimetry with an attention put on ultra-high dose measurements is presented and described. As particularly important in clinical dosimetry for eye-tumor radiotherapy, the surface 2D detectors were developed. The participation of the Institute of Nuclear Physics (IFJ) group in the Cosmos experiment MATROSHKA is described. Also, the new TL materials and measurement methods are presented. [ABSTRACT FROM AUTHOR]

The purpose of this work was to systematically assess the distribution of thermoluminescence (TL) and optically stimulated luminescence (OSL) properties along the length of crystals grown by the micro-pulling-down method, in relation to the microstructure and distribution of activators. We analyzed lithium magnesium phosphate (LiMgPO4; LMP) crystals doped with terbium (Tb; 0.8 mol%) or with a combination of thulium (Tm; 0.8 mol% or 1.2 mol%) and boron (B; 10 mol%). Crystals of several centimeters in length and 3 mm in diameter were cut into 20–40 slices, depending on length. For each sample, TL glow curves and OSL decay curves were examined. Optical microscopy and scanning electron microscopy were used to assess the microstructure and elemental composition of several selected samples. Two-dimensional TL readouts were performed to identify the areas with higher and lower signal emission. Our study showed that there may be significant differences not only in LMP sensitivity along the crystal's axis but also on the surface of the slice. The distribution of activators varies depending on the type of crystals and strongly affects luminescence properties. [ABSTRACT FROM AUTHOR]