13:00 〜 13:30
▲ [17p-A404-1] Progress on Ce:Li6Y(BO3)3 single crystals toward thermal neutron detection
キーワード：Scintillator, Thermal neutron detection, Oxide
The development of efficient, low-cost, and stable solid-state materials for portable thermal neutron detection is highly expected in order to substitute the currently used 3He and BF3 tank detectors. A few Li-based glasses and halide compounds have emerged as candidates, but all of them present critical drawbacks for their practical implementations. Ce:Li6Y(BO3)3 (LYBO) is a priori a very promising oxide candidate that, however, has been disregarded so far due to its disappointingly low light yield, caused by a poor crystalline and optical quality.
Recently, we found that for compounds with a low melting point like LYBO (Tm = 865oC), doping with CeF3 instead of the commonly used CeO2 and carrying out the growth under non-oxidizing atmosphere leads to the successful incorporation of Ce3+ activators. On the other hand, we found that the presence of scattering centers is closely related with the slight incongruent nature of LYBO. These scattering centers can be drastically reduced via annealing at a temperature close to the melting point, so that the scattering path becomes almost invisible. By the combination of the above strategies, namely the efficient Ce3+ doping and the drastic reduction of scattering centers, the light yield of LYBO was systematically improved by 600% to a value of ~4400 ph/n, thus becoming comparable to reference Li-glass GS20. At the same time, the afterglow was reduced by 2 orders of magnitude to a low level of 0.02% @ 50 ms. Consequently, this work demonstrates for the first time the actual potential of Ce:LYBO for thermal neutron scintillation.
Recently, we found that for compounds with a low melting point like LYBO (Tm = 865oC), doping with CeF3 instead of the commonly used CeO2 and carrying out the growth under non-oxidizing atmosphere leads to the successful incorporation of Ce3+ activators. On the other hand, we found that the presence of scattering centers is closely related with the slight incongruent nature of LYBO. These scattering centers can be drastically reduced via annealing at a temperature close to the melting point, so that the scattering path becomes almost invisible. By the combination of the above strategies, namely the efficient Ce3+ doping and the drastic reduction of scattering centers, the light yield of LYBO was systematically improved by 600% to a value of ~4400 ph/n, thus becoming comparable to reference Li-glass GS20. At the same time, the afterglow was reduced by 2 orders of magnitude to a low level of 0.02% @ 50 ms. Consequently, this work demonstrates for the first time the actual potential of Ce:LYBO for thermal neutron scintillation.