Neutron detection with LiCaAlF6 scintillator doped with 3d-transition metal ions

Capability of thermal neutron detection was examined for LiCaAlF6 (LiCAF) scintillators doped with 3d-transition metal ions. Their radioluminescence spectra were measured with an 241-Am source to simulate 6Li(n, α)3H reaction. The sufficiently intense radioluminescence was observed for the Mn, Co and Cu dopants, while only a weak one was observed for Ti, V, Fe and Ni. A Mn doped LiCAF crystal, which showed the highest radioluminescence intensity, was coupled with a Si avalanche photodiode for the examination of its neutron response. It was confirmed that the average current of the photodiode clearly increased under excitation with 13.5 meV neutron flux. -- Highlights: •Neutron detection with 3d-transition metal ions doped LiCaAlF6 is investigated. •Single crystals of Ti, V, Mn, Fe, Co, Ni and Cu doped LiCaAlF6 are grown. •In α-ray induced emission spectra, Mn doped LiCaAlF6 showed highest intensity. •Mn doped LiCaAlF6 coupled with Si-APD exhibited a clear neutron signal