Study on fast luminescence component induced by gamma-rays in Ce doped LiCaAlF6 scintillators

We discuss the origin of the fast luminescence component induced by fast electrons generated in gamma-ray interactions in Ce doped LiCaAlF6 scintillators. Although the slow luminescence component induced by Ce3+ emissions depends on the Ce concentration in the LiCaAlF6 scintillator, the fast component is independent. The fast component is suggested to be generated in the host matrix of the LiCaAlF6 crystal. From quantitative considerations based on Frank-Tamm equation, which shows the light yield of the Cherenkov radiation, the Cherenkov radiation was determined as the origin of the fast component. We, additionally, found that the slow rise time of main Ce3+ emissions in the Ce:LiCaAlF6 scintillator plays an important role to perform the pulse shape discrimination.