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Description
LaBr_{3}:Ce is known as an efficient scintillation material with $\gamma$-ray spectroscopic properties for isotopes identification applications. Energy resolution of industrial detectors is on the order of 3.0% . Material engineering with $Me^{2+}$ co-doping demonstrated an efficient way of improving the proportionality and consequently the energy resolution of the co-doped scintillator [1,2]. Some properties of co-doped crystals are evaluated with respect to the reference: the decay time of the co-doped scintillator becomes more complex with additional 1 or 2 slower components; the light yield increases from the referenced 73000 ph/MeV to 78000 ph/MeV for co-doped material; the energy resolution is improved.
The level of co-doping in industrial crystals has been optimized by balancing the tradeoffs between increase of the principal decay time and improvement of the energy resolution.
The latest generation of industrial detectors with the crystal size 1.5’’x1.5’’ consistently demonstrate an energy resolution of 2.2% at 662 keV.
The temperature dependence of the light yield of co-doped scintillator in the practically interesting range (20; 175)°C is becoming more flat.
The engineered material demonstrates enhanced PSD (Pulse-Shape Discrimination) for discrimination [3]. The PSD property enables the discrimination of the background from $^{227}Ac$ and its daughter products in the decay chain. The PSD makes it possible to actively suppress the contributions in spectroscopic measurements. The same PSD can also be applied in the use of $LaBr_{3}:Ce:Sr$ material in composite neutron detection systems.
Saint-Gobain Crystals is launching the full-scale production of engineered $LaBr_{3}:Ce:Sr$ scintillator in 2017 for the various customized applications. The maximum size of crystals in the detectors are limited to the diameter equals 4’’ and the length up to 10’’.
References:
[1] K. Yang, P. R. Menge, J. Buzniak and V. Ouspenski, “Performance Improvement of Large $Sr^{2+}$ and $Ba^{2+}$ co-doped $LaBr_{3}:Ce^{3+}$ Scintillation Crystals”, IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), pp. 308-311, 2012.
[2] M.Alekhin, J.Haas, I.Khodyuk, K.Kramer, P.Menge, V.Ouspenski and P.Dorenbos. Improvement of $\gamma$-ray energy resolution of $LaBr_{3}:Ce^{3+}$ scintillation detectors by $Sr^{2+}$ and $Ca^{2+}$ co-doping. Appl. Physics Letters, V.102, 161915, 2013.
[3] K.Yang, P.Menge and V.Ouspenski Enhanced $\alpha$ - $\gamma$ discrimination in co-doped $LaBr_{3}:Ce$. IEEE Transactions on Nuclear Science, V.63, N 1, 2016.
