Ytterbium-based scintillators, a new class of inorganic scintillators for solar neutrino spectroscopy

The observed deficit of the solar neutrino flux is now well established. This puzzling problem of todayʹs particle physics could be resolved soon. The most likely explanation would be the vacuum neutrino oscillation phenomenon, indirectly proving the non-zero mass of these fleeting particles. Following the proposition of Raghavan of using 176Yb as a target for low-energy solar neutrino spectroscopy, an intense R&D work has started a few years ago to define a suitable scintillator incorporating a large amount of ytterbium. Recently, the observation of UV scintillation in mixed yttrium/ytterbium aluminium garnets opened the field of investigation to a new class of scintillating crystals with interesting luminescence properties, very attractive not only for neutrino physics but also for radiation detection, in general. Their luminescence properties present some peculiarities that make them interesting by themselves.