Cerenkov counting of low-energy beta-emitters using a new ceramic with high refractive index

The threshold beta-ray energy for Cerenkov photon production can be reduced to about 0.07 MeV by using a transparent ceramic with a high refractive index. This makes it possible to measure the low-energy beta-emitters 14C and 45Ca by Cerenkov counting with efficiencies of 1.5% and 2.3%, respectively.