Current technologies for X-ray detection rely on scintillation from expensive inorganic crystals grown at high-temperature, which so far has hindered the development of large-area scintillator ...arrays. Thanks to the presence of heavy atoms, solution-grown hybrid lead halide perovskite single crystals exhibit short X-ray absorption length and excellent detection efficiency. Here we compare X-ray scintillator characteristics of three-dimensional (3D) MAPbI
and MAPbBr
and two-dimensional (2D) (EDBE)PbCl
hybrid perovskite crystals. X-ray excited thermoluminescence measurements indicate the absence of deep traps and a very small density of shallow trap states, which lessens after-glow effects. All perovskite single crystals exhibit high X-ray excited luminescence yields of >120,000 photons/MeV at low temperature. Although thermal quenching is significant at room temperature, the large exciton binding energy of 2D (EDBE)PbCl
significantly reduces thermal effects compared to 3D perovskites, and moderate light yield of 9,000 photons/MeV can be achieved even at room temperature. This highlights the potential of 2D metal halide perovskites for large-area and low-cost scintillator devices for medical, security and scientific applications.
•Scintillation yield of GAGG:Ce correlates with cerium concentration.•Thermoluminescence intensity decreases with increasing cerium content.•Room temperature light output of GAGG:Ce is almost twice ...lower than below 180K.•Charge traps in GAGG:Ce are generally shallower than in YAG:Ce.
In this paper we report the measurements of pulse height spectra, radioluminescence spectra at various temperatures between 10 and 325K, and low temperature thermoluminescence glow curves of Gd3Al2Ga3O12:Ce. It is shown that the scintillation yield of the studied material correlates with the concentration of cerium and anti-correlates with the thermoluminescence intensity. However, regardless of the cerium content, the yield at room temperature is almost twice lower than below 180K.
In this paper, we report on the scintillation properties and pulse shape discrimination (PSD) performance of new plastic scintillators, EJ-276 and EJ-276G . Cylindrical samples with dimensions of 1×1 ...inch and 2×2 inches were tested. Additionally, four samples 2×2 inches in size were used in stack configurations in order to measure the PSD characteristics of large samples (up to 2×8 inches). The paper covers the measurements of neutron/gamma discrimination, emission spectra, photoelectron yield, and analysis of the light pulse shapes originating from events related to gamma-rays and fast neutrons. The results were compared to data recorded previously using plastic scintillators EJ-299-33, EJ-299-33G, EJ-299-34, EJ-299-34G, and an EJ-301 liquid scintillator.
Display omitted
•LuYAG:Pr and LuAG:Pr,Mo crystals have been grown by the Czochralski method.•Both materials show increased scintillation yields compared to LuAG:Pr.•Mechanisms explaining the observed ...enhancement have been proposed.
In this paper the basic scintillation and thermoluminescence properties of LuYAG:Pr and LuAG:Pr,Mo crystals are reported. It is shown that, primarily, both materials display significantly higher scintillation yields than their prototype LuAG:Pr. The results of radioluminescence, low and high temperature thermoluminescence, and scintillation time profile measurements are analyzed quantitatively to allow us a better understanding of the scintillation process in LuYAG:Pr and LuAG:Pr,Mo, as well as to let us propose or verify possible explanations of the observed yield enhancement.
This paper presents the results of the proton irradiation of silicon photomulipliers (SiPMs) by mono-energetic 170 MeV protons with fluence up to 4.6×109 particles/cm2. In our work, three types of ...silicon photodetectors from Hamamatsu with areas 3×3 mm2 and different subpixel sizes of 25×25 μm2, 50×50 μm2, and 75×75 μm2 were used. The changes in the SiPM dark count rate (DCR) spectrum before and after irradiation in temperatures in the range of 20ˆC to −65ˆC are presented. The influence of the DCR changes on the energy resolution of the 662 keV gamma line from the 137Cs for a non-irradiated GAGG:Ce (1%) scintillator is investigated. The time period of usability of the SiPM detector irradiated by protons in cosmic space was estimated.
This paper presents the results of the fast neutron irradiation (En > 0.5 MeV) of an EJ-276 scintillator performed in the MARIA research reactor with fluence up to 5.3 × 1015 particles/cm2. In our ...work, four samples with size φ 25.4 mm × 5 mm were tested. The changes in the light yield, emission and absorption spectrum and neutron/gamma discrimination using PuBe source before and after irradiation are presented. The figure of merit in neutron/gamma discrimination based on the charge integration method for different neutron fluences and different short gate integration times are determined.
► Scintillation yield of Lu3Al5O12:Pr (LuAG:Pr) can be enhanced by thermal annealing. ► An increase of 17% has already been achieved upon annealing in air or oxygen. ► The acquired data indicate that ...there is room for further improvement.
Effects of thermal annealing in various atmospheres of Czochralski-grown Lu3Al5O12:Pr (LuAG:Pr) crystals on their scintillation yield and energy resolution are discussed. It is shown that annealing in argon, air, or oxygen at 1373K for 48h is a simple way of achieving a ten-odd percent increase of yield together with an improvement of energy resolution. High temperature thermoluminescence measurements indicate significant reductions of trap concentrations in the annealed crystals compared to the “as grown” ones, which correlates well with the observed yield increase. A simple model is proposed to predict further available yield enhancement in LuAG:Pr upon thermal annealing.
Interior of Czochralski-grown (Lu,Y)AG:Pr crystals has been examined by means of several techniques, such as X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, Time-of-Flight Secondary Ion Mass ...Spectrometry, and magnetic susceptibility measurements. Additionally, their luminescence has been monitored at various combinations of a double-beam (X-ray/IR) excitation.
The scintillation properties of cesium-zirconium hexachloride (Cs2ZrCl6) were investigated by γ-ray spectrometry and the Compton Coincidence Technique. The tested cylindrical sample had 20 mm ...diameter and 12 mm height. The crystal shows a high light output of 40 900 photons per MeV as measured by a spectroscopy type photomultiplier with 20 μs pulse integration time under γ-ray excitation at room temperature. A small deviation from linear response as a function of energy deposited in γ-ray absorption or Compton scattering processes, combined with a high light yield, results in good energy resolution equal to 4.3 % at 662 keV and 2.3 % at 2.6 MeV. Due to long lasting scintillation decay the sample properties were studied at different shaping time constants in an analogue spectroscopy chain or using different integration time gates when employing a digital analyzer.
In this paper, five detectors (EJ-270 — single plastic scintillator, EJ-309B5 — single liquid scintillator, and 3 phoswich detectors: EJ-276+GS20, GS20+EJ-276, EJ-309+GS20) were studied in terms of ...simultaneous detection of gamma-rays and slow and fast neutrons. The measurements were carried out in a mixed field of neutron and gamma radiation from an intense (∼106 neutrons/s/4π) PuBe source. The PuBe neutron source was placed in an 18 cm diameter paraffin ball in order to increase the number of slow neutron detections. This paper covers the measurements of the neutron/gamma discrimination, photoelectron yield and analysis of the light pulse shapes originating from events related to gamma-rays, slow neutrons and fast neutrons. Sensitivity to slow neutrons is also briefly discussed. A comparison of n/γ discrimination for all of the tested detectors shows excellent performance of all phoswich detectors. Phoswich configurations tested within the scope of this study allow unambiguously resolve all three types of radiation and show superior performance in comparison with single loaded plastic or liquid scintillators.
PDF
