Dark matter search with CaF2 scintillator at Osaka

A CaF₂ scintillator complex system (ELEGANT VI) is developed to search for the axial-vector coupled dark matter (WIMPs) and study the neutrino-less double beta decay of ⁴⁸ Ca. Active light guides of pure CaF₂ crystals which are on both sides of the central CaF₂(Eu) crystal act as a 4π active shield, combined with surrounding CsI(T1) scintillators. The whole system is at the underground laboratory (Oto Cosmo Observatory) located in Nara. In this article our current status of the investigation are described, especially putting emphasis on the development of flash scaler to do a single photon counting.