Influences of Anticoincidence Shield on Liquid Scintillation Count Rates for Various Kinds of Radionuclides

Three liquid scintillation counters with/without anticoincidence shield have been used to determine the count rates for various kinds of radionuclides. The influences of anticoincidence shield on the count rates can be neglected for α-emitters, β-emitters and β/γ emitters with no β-γ cascade radiation. However, remarkable decreases of count rates are observed when anticoincidence shield is applied for β/γ emitters with β-γ cascade radiations. If liquid scintillation counter with anticoincidence shield is employed as absolute measurement method, the decay properties of the measured radionuclide should be in consideration.