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LaMgAl 11 O 19 :Er single crystals were examined as candidates for scintillators emitting near-infrared luminescence, and their radioluminescence and scintillation detector characteristics were assessed. Upon exposure to X-ray, distinct emission peaks appear at ∼550 and ∼1540 nm and are attributable to Er3+ ions. The decay curves also exhibited characteristic decay times associated with Er3+ ions. Particularly, the 3% Er-doped sample showed a discernible linearity in the dynamic range of dose rate from 1 to 50,000 mGy/h, indicating the potential utility in applications requiring precise and reliable radiation measurements. • Er-doped LaMgAl 11 O 19 crystals were synthesized by the floating zone method. • The samples show a broad emission band at 380 nm due to host and sharp peaks at 550 and 1540 nm due to Er3+. • The 3% Er-doped sample showed a good linearity in the dynamic range of dose rate from 1 to 50,000 mGy/h. [ABSTRACT FROM AUTHOR]

Ce differently (0, 0.01, 0.1, 1, 2 and 5% with respect to Mg) doped LiMgAlF 6 ceramics were synthesized by the spark plasma sintering (SPS) method. In photoluminescence (PL), emission bands appeared at 300 nm with 30 ns day time, and these emission properties were almost the same in scintillation under X-ray irradiation. Further, thermally stimulated luminescence (TSL) was observed after X-ray irradiation, and the primary glow peak temperature was 160 °C with a lower detection limit of ∼10 mGy. • Ce-doped LiMgAlF 6 ceramics were prepared by the spark plasma sintering method. • Photoluminesence and scintillation properties were investigated. • Thermally stimulated luminescence properties were evaluated. [ABSTRACT FROM AUTHOR]

BaCl 2 :Eu transparent ceramics were synthesized by the spark plasma sintering method, and concentration dependence of Eu on optical and scintillation properties was investigated. BaCl 2 :Eu transparent ceramics showed photoluminescence (PL) and scintillation peaks at 400 nm due to 5d–4f transition of Eu2+. The PL and scintillation decay time constants of BaCl 2 :Eu transparent ceramics were ∼400 ns. The PL quantum yields (QY s) of 0.05, 0.1, 0.5, and 1% BaCl 2 :Eu transparent ceramics were 28.5, 25.6, 16.2, and 13.9%, respectively. The afterglow levels of BaCl 2 :Eu transparent ceramics were lower than CsI:Tl single crystal in practical use. The scintillation light yield of the 0.5% doped BaCl 2 :Eu transparent ceramic was 9800 photons/MeV when γ-rays by 137Cs were irradiated. • BaCl 2 :Eu transparent ceramics were synthesized using the SPS method. • We investigated the optical and scintillation properties. • The scintillation peak due to 5d–4f transition of Eu2+ was observed at 400 nm. • The 0.5% Eu-doped sample showed the highest LY (9800 ph/MeV) under 137Cs γ-ray irradiation. [ABSTRACT FROM AUTHOR]

Pr:Li 6 Y(BO 3) 3 and Pr,Ce:Li 6 Y(BO 3) 3 crystals were grown by the Czochralski method. The luminescence properties of the Pr:Li 6 Y(BO 3) 3 and Pr,Ce:Li 6 Y(BO 3) 3 crystals, such as their optical transmission, photoluminescence and X-ray induced luminescence spectra were investigated. The scintillation properties of the multi-channel energy spectrum of the Pr,Ce:Li 6 Y(BO 3) 3 crystal under thermal neutrons and gamma-ray excitation were also studied. The energy resolutions of the Pr,Ce:Li 6 Y(BO 3) 3 crystal, which had a size of 8 × 7 × 2 mm3 , excited by moderated 252Cf for the 10B (n,α)7Li and 6Li (n,α)3H reactions were determined to be 42% and 16%, respectively. The decay time under 320 nm UV light excitation was fitted to be 27 ns. Therefore the Pr,Ce:Li 6 Y(BO 3) 3 crystal is a promising fast scintillator for thermal neutron detection with good energy resolution, fast decay time and possible pulse-height discrimination ability. • Pr3+, Ce3+ co-doped Li 6 Y(BO 3) 3 crystals were grown using Czochralski method. • The energy resolution of Pr,Ce:LYBO crystal for 10B (n,α)7Li reaction is 42%. • The energy resolution of Pr,Ce:LYBO crystal for 6Li (n,α)3H reaction is 16%. • The photoluminescence decay time of Pr,Ce:Li 6 Y(BO 3) 3 crystal is 27 ns. [ABSTRACT FROM AUTHOR]

Abstract In this study, the Gd3+-substituted yttrium aluminum perovskite epitaxial films activated by Ce3+ ions, (YGd)AlO 3 :Ce3+ with Gd content 0–44%, were prepared by liquid phase epitaxy technique and their optical, luminescence, and scintillation properties were studied. The results showed that films with Gd content below 20% had greater photoluminescence and radioluminescence intensities. For higher Gd concentrations, the Ce3+ emission gradually decreased and the Ce3+ decays were accelerated. The model of bidirectional non-radiative energy transfer between Gd3+ and Ce3+ ions and energy migration over the Gd3+ sublattice is suggested and the processes responsible for the observed effects are discussed. Highlights • (GdY)AlO 3 :Ce3+ perovskite scintillators were characterized. • Bidirectional Gd3+-Ce3+ energy transfer in GdYAP:Ce perovskite was proposed. • Gd co-doped YAlO 3 :Ce3+,Gd3+ perovskite films were prepared by liquid phase epitaxy. [ABSTRACT FROM AUTHOR]

Abstract LaAlO 3 perovskite single crystals doped with Ce, Eu or Tb have been grown by micro-pulling-down method. X-ray diffraction analysis confirmed low-temperature rhombohedric phase. Energy-dispersive Laue mapping revealed sub-grains in the grown crystals. For the Ce-doped crystals, very low radioluminescence efficiency was found and the observed emission was ascribed to defects. Photoluminescence spectra were significantly different from the radioluminescence ones. They were significantly quenched at room temperature and the related luminescence showed also unusually high Stokes shift. High radioluminescence efficiency was found for the Tb-doped samples and especially for the Eu-doped ones, which would point to the fact that in LaAlO 3 the scintillation process is more favorable for the luminescence ions which tend to capture an electron first. Highlights • Morphology of the grown rare-earth-doped LaAlO3 crystals was studied. • Role of the growth atmosphere explained by its influence on Ce valence state. • Origin of radioluminescence explained by defect emission in Ce-doped crystals. • High radioluminescence efficiency found for Eu-doped crystals. [ABSTRACT FROM AUTHOR]

The linear response is the key property employed by a radiation detector to determine the accurate intensity of a pulse radiation field. In this study, we investigated the high fluence rate response behavior of a LaBr 3 scintillator. We used a high-intensity pulsed X-ray source called “QiangGuang-I” which could produce an X-ray pulse with a total dose of 100 Gy, full width at half maximum of 20 ± 5 ns, and an average energy of 1 MeV, to test the linear response of the LaBr 3 scintillator. The Lissajous figure method was used in this experiment. The results showed that the fluence rate linear response limit was more than 1.8 × 10 20 MeV/(cm 2 ·s). [ABSTRACT FROM AUTHOR]

We have synthesized the Al 2 O 3 transparent ceramic by using spark plasma sintering (SPS) and investigated the dosimeter and scintillation properties for X-ray detections, in comparison with the single crystal. Under X-ray irradiation, emissions at 300, 400 and 693 nm were observed in both the samples. To identify the origins of these emissions, scintillation decay times were investigated. Based on the results, emissions at 300, 400 and 693 nm are attributed to F + centers, F centers and Cr 3+ impurity ions, respectively. The thermally-stimulated luminescence (TSL) glow curves of both the samples showed a main peak around 50 °C. In addition, glow peaks were observed at 190, 290 and 360 °C. The TSL spectra had broad emission bands in the 300, 400 and 693 nm, which approximately agreed with the scintillation spectra. The TSL response was confirmed to be linear to the irradiation dose for transparent ceramic over the dose range from 0.3 to 1000 mGy while the sensitivity of the single crystal was lower and the response range confirmed was from 30 to 1000 mGy. [ABSTRACT FROM AUTHOR]

Over the past two decades, substantial research has been done on the typical elpasolite scintillators Ce:Cs 2 LiYCl 6 (CLYC) and Ce:Cs 2 LiLaBr 6 (CLLB) for their potential use as neutron/gamma dual-mode detectors. Commonly, the cation or anion alloying will change the luminescence and scintillation properties of the scintillators, such as the good energy resolution of the Ce:Cs 2 LiLa(Br–Cl) 6 (CLLBC) crystal. In this work, ⌀8 mm Ce:Cs 2 Li(LaBr 6) x (YCl 6) 1-x crystals with x = 0.1, 0.2, 0.3 and 0.4 were grown by the vertical Bridgman technique. Then, ⌀25 mm Ce:Cs 2 LiLa 0.1 Y 0.9 Br 0.6 Cl 5.4 crystal was grown for its relatively high optical quality and phase purity. The luminescence and scintillation properties were also investigated. The energy resolution of Ce:Cs 2 LiLa 0.1 Y 0.9 Br 0.6 Cl 5.4 crystal was calculated to be 9.3%. The scintillation decay time were 38 ns and 623 ns under 137Cs irradiation. • Ce: Ce:Cs 2 Li(LaBr 6) x (YCl 6) 1-x crystals were grown using vertical Bridgman method. •⌀25 mm Ce:Cs 2 LiLa 0.1 Y 0.9 Br 0.6 Cl 5.4 crystal with good optical quality was obtained. • Energy levels were calculated and CVL mechanism was displayed. •The photoluminescence decay time of Ce:Cs 2 LiLa 0.1 Y 0.9 Br 0.6 Cl 5.4 crystal was 36.9 ns. •Energy resolution of 9.3% under 137Cs irradiation was obtained. [ABSTRACT FROM AUTHOR]

The emissions of Ce3+ in Ce:YAG are at approximately 550 nm and are generated by the overlapping emission of two transitions 5d → 2F 5/2 (2F 7/2), and their luminescence characteristics are markedly influenced by temperature and ion fluence. In this study, the temperature and ion fluence dependence of Ce3+ emission was investigated using ion beam-induced luminescence (IBIL) at four different temperatures (25, 150, 300, and 450 °C), and potential theoretical explanations for the variation were discussed. Experimental results show that (1) as the temperature increases, the intensity of Ce3+ decreases, and the central peak position continues to redshift; (2) as the temperature rises, the proportion of the high-energy peak at approximately 2.3 eV continuously increases; (3) a double exponential model can describe the evolution of the Ce3+ luminescence intensity with fluence; and (4) the influence of 2 MeV H+ on the luminescence characteristics of Ce:YAG is limited. The luminescence characteristics of the Ce:YAG single crystal deteriorate when exposed to high temperatures. Combined with the observed experimental phenomena, we recommend that the practical operating temperature of the Ce:YAG single crystal in a high ion fluence environment should be as low as 150 °C when possible to ensure a high scintillation yield and good luminescence performance. • Acquiring real-time and in-situ luminescent data on Ce:YAG single crystal with IBIL. • Temperature has a significant influence on Ce:YAG performance than fluence. • Ionic excitation allows thermal quenching of Ce3+ at lower temperatures. • Evaluating the radiation resistance of samples with double exponential model. • The working temperature of Ce:YAG should not exceed 150 °C in high ion fluence. [ABSTRACT FROM AUTHOR]

The luminescence and scintillation properties of Lu 0.8 Gd 1.2 SiO 5 :Ce and Lu 1.8 Gd 0.2 SiO 5 :Ce single crystals are compared. At 662 keV γ-rays, light yield (LY) value of 29,800 ph/MeV obtained for Lu 1.8 Gd 0.2 SiO 5 :Ce is much higher than that of 20,200 ph/MeV obtained for Lu 0.8 Gd 1.2 SiO 5 :Ce. The energy resolution of 6.0% obtained for Lu 0.8 Gd 1.2 SiO 5 :Ce is better than that of 7.7% for Lu 1.8 Gd 0.2 SiO 5 :Ce due to its better intrinsic resolution and proportionality of LY. The LY and energy resolution for α-rays, as well as a LY ratio under excitation with α- and γ-rays (α/γ ratio) are also determined. The intrinsic LY and light loss coefficient under excitation with α- and γ-rays are evaluated. The photofraction at 662 keV γ-rays is also determined and discussed. [ABSTRACT FROM AUTHOR]

Fluoroborosilicate (SBF anc :SiO 2 + B 2 O 3 +AlF 3 + NaF + CaF 2) glasses with different CeF 3 concentrations were fabricated by melt quenching technique to examine the scintillation properties of these glasses. The density and refractive index increase with an increase in CeF 3 concentration. The structural properties of glasses were studied in the range of 800–4000 cm−1 using FT-IR transmittance spectroscopy. Luminescence characteristics of Ce3+:SBF anc glasses with an intensity peak around ∼345 nm (5d→4f) were studied using photo (λ exc = 303 nm) and X-ray excited luminescence techniques. The energy transfer (ET) between Ce3+ -Ce3+ ion pairs taking place via dipole-dipole type interaction for the concentration quenching of Ce3+ emission on the basis of Dexter and Schulman theory. The PL decay curves can be fitted by a double exponential function with the decay times 64.28–99.87 ns and 15.78–21.29 ns for slow and fast decay components, respectively. The highest integrated light emission intensity of Ce3+:SBF anc glasses stimulated by X-ray is 35% of commercial Bi 4 Ge 3 O 12 crystal and can be used for the scintillator materials. • The transmittance spectra of glasses were measured in UV, Visible and mid-IR region. • Concentration quenching of Ce3+ emission is analyzed by the Dexter-Schulman theory. • PL, X-ray excited luminescence and decay curves of glasses were investigated. • The X-ray intensity of SBF anc Ce 0.30 glass is about 35% of that of a commercial BGO. [ABSTRACT FROM AUTHOR]

In this work, the Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators of the composition ratio 25Gd 2 O 3 :10CaO:10SiO 2 :(55−x)B 2 O 3 :xCeF 3 , have been fabricated by using the melt-quenching technique. The doping concentration of the Ce 3+ was varied from 0.05 mol% to 2.5 mol%. The 4f-5d transition of the Ce 3+ allowed scintillation with a fast decay time. The absorption spectrum, X-ray induced emission spectrum, photo luminescence spectrum, laser luminescence spectrum and decay time of the scintillators were measured for studying the luminescence properties. From the X-ray induced emission spectrum result, we checked the trend between doping concentration and light yield. The laser induced luminescence spectrum was measured while changing the temperature from 300 K to 10 K. We also measured the decay time by using the laser excitation of the 0.15 mol% Ce 3+ doped glass scintillator. [ABSTRACT FROM AUTHOR]

1300 or 1400 °C pre–sintered Al/Ce/Mg:SrHfO 3 and Al/Ce:SrHfO 3 ceramics were prepared by the Spark Plasma Sintering (SPS) in order to search for a new scintillation material with a high–effective atomic number(Z eff ) and good light output. The SrHfO 3 has a high Z eff of 60, and high gamma–ray detection efficiency is expected. Meanwhile it has a high melting point of over 2500 °C, and single crystal is hard to be grown. On the other hand, high melting materials can be prepared as ceramics, and the SPS method is a simple process to fabricate the ceramics within a few hours. Thus, we prepared the samples using the SPS method, and their optical and scintillation properties were investigated. We found that Al/Ce/Mg:SrHfO 3 and Al/Ce:SrHfO 3 ceramics had an emission wavelength at around 400 nm originating from 5d–4f transition of Ce 3+ . Moreover, Al/Ce/Mg:SrHfO 3 pre-sintered at a temperature of 1400 °C had a light output of approximately 5,000 ph/MeV. In this paper, the light output of Mg-co-doped samples was improved compared with the Mg-free ones. The light output also depends on the pre-sintering temperature. [ABSTRACT FROM AUTHOR]

It was shown that annealing ZnO and ZnO:Ga initial powders and ceramics in different atmospheres significantly changes the characteristics of the studied samples. Two main luminescence bands of different origins were observed in powders at 540 nm and 580 nm. Annealing either in vacuum or in Ar:H 2 atmosphere increased intensity of green luminescence with peak at 540 nm whereas annealing in air enhanced a luminescence band with peak at 580 nm in the powders. Corresponding changes in luminescence kinetic properties were observed. Annealing of the ceramics in vacuum and air did not affect the luminescence properties, while annealing them in Ar:H 2 atmosphere increased green luminescence intensity of undoped ceramics and excitonic luminescence intensity of doped ones. Comparison of the X-ray, gamma-ray and cathode-ray excited luminescence lead to conclusion that the enhancement of luminescence intensity took place in surface layer of about 100 μm thickness. [ABSTRACT FROM AUTHOR]

The luminescence and scintillation properties of YGd 2 Al 2 Ga 3 O 12 :Ce and LuGd 2 Al 2 Ga 3 O 12 :Ce single crystal scintillators were compared. The light yield (LY) and energy resolution were measured using R6231 photomultiplier. At 662 keV γ-rays, high LY value of 37,900 ph/MeV and energy resolution of 7.0% obtained for YGd 2 Al 2 Ga 3 O 12 :Ce are slightly better than the values of 35,400 ph/MeV and 7.6% obtained for LuGd 2 Al 2 Ga 3 O 12 :Ce. The ratio of LY values under excitation with α- and γ-rays (α/γ ratio) was also determined. The LY dependence on amplifier shaping time was measured in order to investigate the timing characteristics in the scintillation response. The estimated photofraction in pulse height spectrum of 662 keV γ-rays and the total mass attenuation coefficient at 662 keV γ-rays were also determined and compared with the theoretical ones calculated using the WinXCom program. [ABSTRACT FROM AUTHOR]

The paper is devoted to investigation of the luminescent properties of Dy 3+ and Dy 3+ -Ce 3+ doped single crystalline films (SCF) grown by LPE method from PbO–B 2 O 3 flux. We have found that the YAG:Dy and YAG:Dy,Ce SCFs possess bright cathodoluminescence in the visible range and good scintillation figure of merit. For this reason LPE grown YAG:Dy and YAG:Dy,Ce SCF are proposed for different applications, namely, as cathodoluminescence screens or screens for microimaging. The Dy 3+ co-doping can be also proposed for improvement of the scintillation efficiency of the Ce 3+ doped garnet compounds in the SCF form due to Dy 3+ → Ce 3+ energy transfer and removing the trap related centers in the above RT range. [ABSTRACT FROM AUTHOR]

In recent years, there has been increasing demand for a scintillator showing near-infrared (NIR) luminescence owing to the potential for radiation monitoring applications. In this study, Pr-doped Bi 4 Ge 3 O 12 (BGO) single crystals were prepared by the floating zone method to explore candidates as a NIR scintillator, and the luminescence and dose-rate response properties of Pr-doped BGO were studied. Both photoluminescence and scintillation peaks appeared at 400–600 nm due to Bi3+, and sharp emission peaks by Pr3+ were also confirmed at 480–1100 nm, with consistent decay times. Further, to investigate performance as a scintillation detector, a linearity of the response to X-ray exposure dose rate was evaluated. Among the samples, the 0.5% Pr-doped BGO showed the highest sensitivity with the lowest detection limit of 0.006 Gy/h. • ● Pr-doped Bi 4 Ge 3 O 12 single crystals were grown by the floating zone method. • The emission due to Pr3+ 4f–4f transitions was observed in the visible–NIR range. • The NIR scintillation intensity was proportional to the X-ray exposure dose rate. • The lowest detection limit was 0.006 Gy/h when the 0.5% Pr-doped sample was used. [ABSTRACT FROM AUTHOR]

The luminescence and scintillation properties of ZnMo 1-x W x O 4 (x = 0, 0.0022, 0.0088) crystals grown by low thermal gradient Czochralski technique were studied in a temperature range of 10–300 K. The good optical transparency above the fundamental absorption of crystals were obtained for all the samples. The luminescence light yield enhancement and slowing of the decay time were observed with lowering the temperature for W doped samples under 4.42 eV excitation. Improvement in scintillation light yield with W doping in ZnMoO 4 crystals was observed and found 76% that of ZnWO 4 crystal at 10 K for 0.88 mol% W doped ZnMoO 4 sample. An additional TSL band was observed for the W doped samples in the temperature range of 70–100 K. The enhancement in scintillation light yield at low temperature with W doping in ZnMoO 4 crystal are quite encouraging to use it as a cryogenic phonon scintillation detector for the neutrinoless double beta decay search of 100Mo. • Luminescence and scintillation of W doped ZnMoO 4 crystal are studied in 10–300 K. • The luminescence decay time becomes slow at low temperature with W doping. • The light yield improved significantly at 10 K with W doping in ZnMoO 4. • A TSL band was observed for W doped samples at low temperature. • The W doping in ZnMoO 4 improved optical quality and scintillation yield. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a group of Lu2SiO5:Tb (LSO:Tb) scintillating layers with a Tb concentration between 8% and 19% were investigated by means of synchrotron and laboratory techniques. The scintillation efficiency measurements proved that the highest light yield is obtained for a Tb concentration equal to 15%. At higher concentration, quenching processes occur which lower the light emission. The analysis of the reciprocal space maps of the (082) (280) and (040) Bragg reflections showed that LSO:Tb epilayers are well adapted on YbSO substrates for all the investigated concentrations. The spatial resolution tests demonstrated the possibility to achieve a resolution of 1 μm with a 6 μm thick scintillating layer. [Copyright &y& Elsevier]

Abstract: The work is dedicated to the development of scintillating screens based on the single crystalline films (SCF) of Ce,Tb doped Lu-based silicates, perovskites and garnets grown by the liquid phase epitaxy method. We confirm in this work the presence of the Ce → Tb energy transfer in LSO and LuAP hosts. We also show that in Ce–Tb doped LuAG SCF, the effective Tb → Ce energy transfer is observed. This results in increasing the light yield of the luminescence of double doped LuAG:Ce,Tb SCF up to 25–30% with respect to single Ce doped (Y,Lu)AG SCF counterparts at optimal ratio of Ce/Tb ions. [Copyright &y& Elsevier]

Abstract: The work is dedicated to the development of scintillating screens based on single crystalline films (SCF) of Ce doped Lu–Y–Al perovskites grown by the liquid phase epitaxy method. We show in this work that Lu1−xYxAP:Ce SCF with very good structural and optical perfection can be grown from the PbO-based flux onto YAP substrates in all range of x-values. We also found the Lu1−xYxAP:Ce SCF can be crystallized by LPE method from the lead free BaO–B2O3–BaF2 flux onto YAP substrates in the range of x values up to 0.4 formula units. [Copyright &y& Elsevier]

Abstract: The paper is dedicated to development of the scintillators based on single crystalline films of Ce doped (GdLaYLu)3(AlGaSc)5O12 multi-component garnets onto Gd3Ga5O12 substrates using the liquid phase epitaxy method. [Copyright &y& Elsevier]

Abstract: The paper is dedicated to development of scintillators based on the single crystalline films of Ce3+ doped Lu2SiO5 (LSO:Ce) and Y2SiO5 (YSO:Ce) orthosilicates grown by Liquid Phase Epitaxy method onto YSO substrates from melt-solutions based on the PbO–B2O3 flux. We also compare the luminescent and scintillation properties of Ce doped LSO:Ce and YSO:Ce single crystalline films with those of their single crystal counterparts, grown by the Czochralski method. [Copyright &y& Elsevier]

Abstract: We examined basic luminescence properties and radiation response of sodium borate glass scintillators activated with Pb2+, Cu+, Ti4+, V5+, W6+ and Yb3+ ions, respectively. These glasses had more than 80% transparency for emission wavelength range, and strong absorption bands due to the charge transition of the ions were observed. In the photoluminescence spectra, all glasses demonstrated intense emission peak in visible region, which are corresponding to the ions with s2 (Pb2+), d10 (Cu+) and d0 (Ti4+, V5+, W6+) configuration. Additionally charge transfer emission was observed in Yb3+-doped glass. When 241Am 5.5 MeV alpha-ray excited the glasses, they showed weak emission intensity because of low energy transfer efficiency from host lattice to emission center. By 241Am irradiated pulse height spectra, Cu+-doped glass demonstrated the highest scintillation output in the glasses. [Copyright &y& Elsevier]

Abstract: Cerium-doped lanthanum bromide (LaBr3:Ce) crystals offer a range of improved scintillation properties over traditional NaI:Tl crystals for in situ gamma spectrometry. At present, however, it remains unclear whether the internal radioactivity of LaBr3:Ce detectors compromises their suitability for low-level activity radioisotope measurements of natural sedimentary deposits, such as those required in luminescence and electron spin resonance (ESR) dating. In this study we investigate the suitability of a commercial LaBr3:Ce detector for measuring individual concentrations of 40K, 238U and 232Th using predefined ‘energy windows’ from gamma ray spectra. Performance tests have been undertaken using reference materials with well-constrained radioisotope concentrations (the Oxford calibration blocks) and compared with results obtained for a NaI:Tl detector of the same geometry. These tests reveal that the LaBr3:Ce detector has a non-negligible intrinsic activity that needs to be accurately quantified prior to measuring any gamma ray spectra in the field. Compared to the NaI:Tl detector, the energy resolution of the LaBr3:Ce detector is improved by a factor of two, or more, for the main indicator isotope photopeaks in the 40K, 238U and 232Th decay series. Signal-to-noise ratios for the LaBr3:Ce detector show a 25–35% improvement over those of the NaI:Tl detector. In addition, the LaBr3:Ce detector is characterised by suitable energy linearity over the full spectral range of interest for the 40K, 238U and 232Th decay series. Replicate gamma ray measurements made with the LaBr3:Ce and NaI:Tl detectors for 20 natural sedimentary samples from the Lower Tejo River basin, Portugal, and the Duero River basin, Spain, yield consistent radioisotope concentrations and gamma dose rate estimates. These results are encouraging and suggest that LaBr3:Ce detectors can provide suitable estimates of individual radioisotope concentrations in low-level activity (0.5–1.5 Gy/ka) environments, providing that their intrinsic activity is adequately measured and subtracted from field spectra. Our comparison also reveals that subtraction of the intrinsic activity from LaBr3:Ce spectra produces a significant reduction in the precision with which radionuclide concentrations can be determined using the ‘energy windows’ approach. This shortcoming necessitates longer counting times in natural sedimentary environments and overshadows the practical advantages that LaBr3:Ce detectors might otherwise offer for luminescence and ESR dating applications. [Copyright &y& Elsevier]

Abstract: Micro-pulling down (μ-PD) method allows to prepare single crystals quickly and relatively inexpensively. Since it is a melt growth and taking into account segregation phenomena, the μ-PD method allows also to obtain single crystals characterized by dopant concentration gradients. Especially, taking the advantage of the grown crystal high aspect ratio, it allows to prepare crystalline samples with variable and wide range concentrations of dopants. These samples can help in understanding the correlation between dopant concentration and luminescence properties. [Copyright &y& Elsevier]

Abstract: The single crystalline Lu3Al5O12 (LuAG) and Y3Al5O12 (YAG) garnet layers doped by Ce3+ ions were grown by the liquid phase epitaxy from the flux. The effect of the flux composition, growth conditions, and substrate polishing on the layer morphology, creation of defects, and on optical and emission properties of layers was studied. The defects typical of the epitaxial growth are discussed. [Copyright &y& Elsevier]

Abstract: Nd3+ 1%, 5% and 10% doped BaF2 single crystals were grown by the micro-pulling down method. Photoluminescence properties, including excitation and emission spectra and luminescence decay were measured under synchrotron radiation excitation at the Superlumi station in HASYLAB at DESY (Hamburg, Germany). The Nd3+ related 5d-4f emission lines peaking around 180 nm, 230 nm, and 260 nm, identified as the 5d–4Ij, 5d–4Fj, and 5d–2Gj transitions, were observed under 140–168 nm excitation. In photoluminescence decay under the 160 nm excitation, the dominant component decay time is about 12, 2.5 and 1.2 ns for Nd3+ 1%, 5% and 10% concentration, respectively. The decay time shortening is explained by the concentration quenching effect. Transmittance of Nd1% sample is about 80% for wavelengths above 185 nm. Finally, gamma-ray responses, non-proportionality and energy resolution of Nd1% sample were compared with the undoped BaF2 scintillator. The light yield of the Nd1%:BaF2 is about 93% of that of undoped BaF2. ©2009 Elsevier Ltd. All rights reserved. [Copyright &y& Elsevier]

Abstract: Lutetium borates and phosphates doped with RE3+ ions are perspective scintillators. In the paper, the results of the luminescence spectroscopy of LuPO4 and LuBO3 doped with Pr3+, Ce3+, Tb3+ and Eu3+ under synchrotron radiation excitation are presented. The processes of the energy transfer from the host lattice to the luminescence centers are considered. The creation of excitons at the edge of fundamental absorption region is shown. The bandgap values for lutetium borate and phosphate were estimated. [Copyright &y& Elsevier]

Abstract: A set of recurrent equations for characteristic functions which describes the photon statistics of the scintillation event is presented. The solution of this set of equations provides non-Monte-Carlo approach for estimation of the yield and intrinsic energy resolution of a scintillator based on the electronic structure and corresponding dielectric functions of the substance. It is shown that the yield and energy resolution is connected not only with statistics of δ-electrons and Auger cascades, but also with peculiarities of luminescence excitation spectra for photons with energies below 100–200 eV. [Copyright &y& Elsevier]

Abstract: A set of terbium-doped silicate glasses densified up to 1050°C was prepared by the sol–gel method. A broad range of dopant concentrations (0.001–10mol%) was considered together with an undoped sample as a reference. The effects of a high-temperature (1600–1800°C) post-densification rapid thermal treatment (RTT) on the luminescence properties of the samples were investigated. RTT enhances the scintillating efficiency of the samples increasing the radio-luminescence intensity up to two orders of magnitude. The relevant effects induced by RTT on radio- and photo-luminescence spectra (RL, PL) and on PL decay curves indicate the occurrence of modifications of the surroundings of luminescence centres. [Copyright &y& Elsevier]

Abstract: Cerium doped YAG nanopowders with grain size have been synthesized by co-precipitation method. Time-resolved luminescence characteristics have been studied. The results obtained have been compared with the luminescence characteristics for well-studied YAG single crystals. In contrast to cerium doped YAG crystals, cerium doped nanocrystal does not reveal luminescence bands due to antisite defects under electron beam pulse and X-ray excitations at 80–300K temperature range. It was detected that decay kinetic of related emission in the nanocrystal can be approximated by two exponents with time constants and at 290K. It is faster than single exponential decay () of cerium ions emission in YAG crystals. The origin of differences in luminescence characteristics for cerium doped nanocrystals and single crystals will be discussed. It is suggested that special sites which are closely related to surface states have an influence on luminescence properties of cerium doped YAG nanocrystals. [Copyright &y& Elsevier]

Abstract: Ceramics ZnO:Zn of 20mm diameter and 1.6mm thickness with an optical transparency up to 0.33 in the visible region have been prepared by hot pressing technique. Scintillating and luminescent characteristics such as emission spectra, decay time, yield, and TSL glow curve have been measured under X-ray excitation. Two emission bands peaking at 500 and 380nm were detected, the light output was about 80% of that for standard BGO scintillator, main decay constant was . The obtained data allow us to consider the ZnO:Zn ceramics as a perspective scintillator. Finally, the investigation shows that other ZnO-based fast scintillators can be fabricated in the form of optical ceramics. [Copyright &y& Elsevier]

Abstract: The influence of thermal treatment (TT) and irradiation by -quanta (60Co, 1.25MeV) in the range of absorbed doses on the absorption, luminescence and light yield (LY) of scintillators based on (LuAG:Ce) single crystalline films (SCF) grown by LPE from the Pb-based flux is studied. It has been shown that transformation of the and valent states of iron and lead trace impurities cause the change in the optical absorption of SCF induced by the TT in air and vacuum in the range of annealing temperatures of . Possible types of radiation defects in LuAG:Ce SCF induced by -radiation are analyzed. [Copyright &y& Elsevier]

Abstract: Combined radioluminescence and thermoluminescence experiments on the co-doped scintillator material CsI:Tl, Eu were extended in the present investigation to a sample with diminished europium concentration. Simulations based on postulated rate equations with empirically adjusted parameters are consistent with observed insensitivity of afterglow suppression to europium concentration for sufficiently short radiation times. [Copyright &y& Elsevier]

Abstract: Luminescent properties and the energy transfer from host to ions are analyzed in single crystalline films (SCF) of YAlO3:Ce (YAP:Ce), :Ce (YLuAP:Ce) and LuAlO3:Ce (LuAP:Ce) perovskites in comparison with their single crystal (SC) analogues using the time-resolved luminescence spectroscopy under synchrotron radiation excitation. It is shown that the main peculiarity of luminescent properties of YAP:Ce, YLuAP:Ce and LuAG:Ce SCF is determined by the extremely low concentration of and antisite defects and vacancy-type defects in SCF as compared to SC. The advantages of phosphors based on (Y-Lu)AP:Ce SCF are due to the absence of emission and trapping centers in these SCF which are connected with the above mentioned bulk crystal defects. [Copyright &y& Elsevier]

Abstract: Luminescence and scintillation properties of single crystalline films (SCF) of Ce- and Pr-doped (YAG) and (LuAG) garnets were analysed and compared with their bulk single crystal (SC) analogues. It was shown that the main peculiarities of luminescent properties of Ce- and Pr-doped YAG and LuAG SCF are due to the absence of and antisite defects (AD) and to the extremely low concentration of vacancy-type defects in SCF with respect to SC. In SCF the absence of the AD-related traps results in faster energy transfer to the emission centres and accelerated scintillation response. [Copyright &y& Elsevier]

Changes in the radiation-induced transparency of scintillating and wavelength-shifting fibers were studied by means of on-line-induced absorption coefficient measurement during and after gamma irradiation. It was found that the main contribution to radiation damage was caused by reactions between luminescent molecules. The time dependence of the radiation-induced absorption coefficient was analyzed in the broad spectral range (420–735 nm) and compared with kinetic models of the processes of absorption center build-up and recovery. The latter has been recently published for these fibers and a lower dose rate in the range of 0.002–0.01 Gy s-1. Good agreement was reached between the low-dose and the presented high-dose measurements (dose rate 4.2 Gy s-1). The parameters calculated in this kinetic model are applicable to prediction of the fiber behavior in particle physics experiments. [Copyright &y& Elsevier]

Thermostimulated and photostimulated luminescence of ZnWO4, ZnWO4:Fe and ZnWO4:Mo crystals irradiated at low temperatures by X-rays or UV photons was studied in the temperature range 4.2–300 K in order to clarify the creation and recombination processes of the elementary colour centres. The connection of the luminescence phenomena with the self-trapped holes has been revealed. [Copyright &y& Elsevier]

Luminescence of a CaWO4 scintillator was studied in the temperature range 77–500 K using intense laser excitation in the 450–600 nm spectral region. Characteristics of the observed blue emission are similar to those of the intrinsic luminescence of calcium tungstate. The emission is concluded to be caused by cascade excitation of CaWO4 that results in a two-photon excited (TPE) luminescence. The features of TPE luminescence of CaWO4 are analysed in comparison to those obtained with UV and X-ray excitation. [Copyright &y& Elsevier]

ZnWO4, ZnWO4:Fe and ZnWO4:Mo crystals were investigated by the methods of time-resolved spectroscopy in the temperature range of 4.2–300 K. It is shown that the Mo and Fe impurities significantly reduce the light yield of ZnWO4. The main 2.5 eV emission of ZnWO4 and the 1.77 eV emission band of ZnWO4:Mo are shown to originate from the triplet excited state of the WO6 and MoO6 complex, respectively. In ZnWO4:Fe,Mo the MoO6 emission band is shifted to lower energies due to the perturbing influence of the iron impurity. No perturbing effect of Fe or Mo ions was observed for the main emission of ZnWO4:Fe and ZnWO4:Mo. The creation spectrum of self-trapped holes was measured for ZnWO4, ZnWO4:Fe and ZnWO4:Mo crystals in the energy region of 4–30 eV. [Copyright &y& Elsevier]

Luminescence properties of heavily Yb-doped Lu3Al5O12 (Yb:LuAG) and Lu3Ga5O12 (Yb:LGG) single crystals grown by micro-pulling-down method were characterized. Charge transfer luminescence of Yb3+ was observed in both crystals. Photoluminescence spectra, temperature dependence of emission intensity and decay kinetics of these crystals were studied. Mean decay time of about 24 ns at 90 K (Yb5%:LuAG) and 21 ns at 110 K (Yb5%:LuGG) were observed. Strong thermal quenching at room temperature was measured for both Yb:LuAG and Yb:LGG. [Copyright &y& Elsevier]

Room temperature radioluminescence and photoluminescence decay kinetics measurements of Ba-doped PbWO4 crystals were compared with those of undoped and Mo-doped samples. Photoluminescence decay measurements focus on the coexistence of the immediate (fast) decay having a decay time of a few nanoseconds with slower delayed recombination decay processes. The radioluminescence emission peaking at 500 nm in Ba-doped crystals is similar to that observed in Mo-doped samples. However, photoluminescence of the Ba-doped crystals shows much faster decay kinetics with respect to that of PbWO4:Mo. Wavelength-resolved thermally stimulated luminescence data (10–300 K) provides complementary information about trapping states and is correlated to photoluminescence decay kinetics. [Copyright &y& Elsevier]

Rod-shaped (Lu1-xYbx)3Al5O12 with x=0.05, 0.15, 0.30 and (Y1-xYbx)AlO3 with x=0.05, 0.10, 0.30 single crystals were grown by the micro-pulling-down method. Edge-defined film-fed growth method was used to prepare (Y0.9Yb0.1)VO4 crystal, while Ca8(La1.98Yb0.02)(PO4)6O2 crystal was grown by the Czochralski method. Luminescence of these crystals was studied with main attention paid to the charge transfer emission of Yb3+. Temperature tuned decay times in the time scale of units—tens of nanosecond was measured as a feature possibly interesting for an application in scintillation detectors in positron emission tomography. [Copyright &y& Elsevier]

In PbWO4(PWO) crystals grown by Czochralski method the influence of atmosphere of the growth (O2, air) and doping with the rare-earth ions of different types (A3+=Lu3+, Gd3+,Tb3+,Eu3+ as well as doubly doped A3+–Li+) on light yield and luminescence decay were analyzed. PWO scintillator with the ultra-fast (τ=0.5 ns) main component of luminescence decay (87% of total light yield) was obtained using the O2-growth atmosphere and doping by Eu2O3 at a concentration of 5000 ppm. It is concluded that the decrease of decay constant of the main scintillation component is the result of the resonant energy transfer between the centers of “blue” PWO luminescence (λmax=420 nm) and the 4f–4f-transitions of Eu3+ ions in this spectral region. [Copyright &y& Elsevier]

The state of the art of core–valence luminescence (CVL) in a number of halides (BaF2, CsCl, LiBaF3, etc.) is analysed. The following items are discussed: common properties of CVL, a suppression of slow emission component in BaF2, an effect of secondary excitation density on intensity and decay profile of the emission, a neutron–gamma discrimination, spectrum simulations, impurity-associated CVL, an origin of slow- and long-wavelength CVL components, a lattice relaxation, vibrations of lattice environment and phonon broadening of the emission bands.Experimental results on impurity-associated CVL of Rb1-xCsxBr (x<0.2) are presented and discussed. It is shown that the impurity-associated luminescence gives us a convenient way for the improvement of light output and variation of the emission wavelength of the scintillators. [Copyright &y& Elsevier]

This study reports on the crystal growth, luminescence, and scintillation performance of a novel elpasolite K 2 LiCeCl 6 scintillator. The single crystal of this material was grown by the two-zone vertical Bridgman technique. The luminescence and scintillation performance were studied under X-, γ -rays, and α -particles excitation at room temperature. The fast scintillation response and α -particles and γ -ray separation capability reveal that this scintillator can be used as a dual-mode γ -rays and thermal neutron detector. • Novel elpasolite K 2 LiCeCl 6 crystal scintillator was developed. • The luminescence properties are studied by using various radiation sources. • Three decay time components were found. • Pulse shape discrimination with gamma-ray and alpha particle was measured. [ABSTRACT FROM AUTHOR]

Abstract: Basic optical properties and radiation responses of undoped, Tm3+ 1.0% and 2.0% activated Ca3(BO3)2 (CBO) crystalline scintillator prepared by the micro-pulling down (μ-PD) method are reported. Tm3+: CBO crystals showed three weak absorption bands around 190, 260 and 350 nm, owing to the Tm3+ 4f–4f transition. Strong blue luminescence peaks at 360 and 460 nm which are ascribed to the 1D2–3H6 and 1D2–3F4 transitions of Tm3+ respectively were observed under 241Am 5.5 MeV α-ray excitation. The scintillation light yield of 2.0% Tm3+-doped CBO crystal was evaluated to be about 250ph/n from the 252Cf excited pulse height spectrum. [Copyright &y& Elsevier]

Abstract: The goal of this study is to determine if cerium-doped oxyorthosilicate scintillators can be used as Optically Stimulated Luminescence (OSL) detectors, possibly offering alternative OSL materials as well as allowing the design of instruments combining passive (OSL) and active (scintillation) detection. The OSL of three common scintillators, Y2SiO5:Ce (YSO), Gd2SiO5:Ce (GSO), and Lu2SiO5:Ce (LSO), were tested. The property which makes these compounds good scintillators, efficient recombination of electron-hole pairs created by ionizing radiation, should make them poor candidates for OSL materials, since OSL requires the creation of electron-hole pairs trapped separately in defects in the crystal lattice. However, defects in the crystal structure can provide a pathway for the OSL phenomenon to take place. Based on the stimulation and emission OSL spectra of the oxyorthosilicates, a CW-OSL reader was built and used to test the samples'' OSL capabilities. The results showed that YSO showed promising OSL, characterized by a strong initial OSL intensity and fast OSL decay, while GSO and LSO were impractical for OSL applications due to low response and high background signal, respectively. Further characterization of YSO included the determination of the OSL dose response and the characteristics of OSL decay curves. The results are compared to carbon-doped aluminum oxide (Al2O3:C), a common OSL dosimetric material. [Copyright &y& Elsevier]