33000 Photons per MeV from Mixed (Lu0.75Y0.25)3Al5O12:Pr Scintillator Crystals

(LuxY1-x)3Al5O12:Pr (x = 0.25, 0.50, 0.75) crystals have been grown by the Czochralski method and their scintillation properties have been examined. Compared to the well-respected LuAG:Pr scintillator, which has so extensively been studied in the recent years, the new mixed LuYAG:Pr crystals display markedly higher light yields, regardless of the value of x. In particular, (Lu0.75Y0.25)3Al5O12:0.2%Pr characterized by a yield of 33000 ph/MeV, an energy resolution of 4.4% (at 662 keV), and a density of 6.2 g/cm3, seems to be an ideal candidate to supercede Lu3Al5O12:0.2%Pr (19000 ph/MeV, 4.6%, 6.7 g/cm3) in various applications. The observed enhancement of light output following the partial substitution of lutetium by yttrium is most probably related to some specific differences in distributions of shallow traps in particular materials

Spectroscopy and Thermoluminescence of LuAlO3:Ce

The present status of the LuAlO3:Ce scintillator is reviewed. Scintillation mechanism of this material is based on capture by Ce3+ of holes and then electrons from their respective bands. Results of spectroscopic and thermoluminescence experiments are presented to support this model

Vacuum referred binding energies of the lanthanides in chloride, bromide, and iodide compounds

A study on Er3+ and Yb3+ luminescence excitation in Cs3Y2I9, Cs2NaYBr6, Cs3Lu2Br9, YCl3, YBr3, and YI3 is presented. The focus is on determining the energy of the charge transfer band, i.e., the energy needed to transfer an electron from the halide anion (Cl, Br, I) to either Yb3+ or Er3+. Those energies together with published spectroscopic information on other lanthanides in the compounds are used to construct vacuum referred binding energies (VRBE) schemes by employing the chemical shift model. Also, VRBE schemes of seven other halide compounds are constructed based on available spectroscopic data. The systematics in the binding energy at the valence band top and conduction band bottom of the thirteen compounds with changing type of halide and with changing compound composition is discussed

Improved scintillation proportionality and energy resolution of LaBr3LaBr_3:Ce at 80 K

Using highly monochromatic synchrotron X-rays in the energy range from 10.5 keV to 100 keV the temperature dependence of nonproportionality and energy resolution of LaBr3 scintillators doped with 5% Ce3+ were studied at 80K, 295K, and 450K. Improvement of the proportionality and better energy resolution was observed on lowering the temperature. This effect suggests that the already outstanding energy resolution of LaBr3:Ce can be improved even further. It also may provide new clues to better understand the processes that cause nonproportionality of inorganic scintillator response.Comment: 5 pages, 2 figures submitted for publication at Nucl. Instr. Meth.