Prompt gamma rays from fast neutron induced reactions on cerium and chlorine

Prompt gamma rays of cerium and chlorine were investigated with the FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) instrument operated at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching. The gamma radiation was emitted from (n,n’), (n,p) and (n,α) reactions induced by the irradiation of a cerium(III) chloride (CeCl 3 ) sample with a beam of fission neutrons. Additionally, a polyvinylchloride (PVC, (C 2 H 3 Cl) n ) sample was irradiated to verify possible interferences between gamma lines of cerium and chlorine. We identified 87 prompt gamma lines of cerium and chlorine. From these, we assigned 58 lines to the (n,n’) reaction in cerium (one for 136 Ce, 41 for 140 Ce and 16 for 142 Ce), 23 to the (n,n’) reaction in chlorine (15 for 35 Cl and 8 for 37 Cl), 5 lines to the 35 Cl(n,p) 35 S reaction and 1 line to the 35 Cl(n,α) 32 P reaction. We present relative intensities and fast-neutron spectrum-averaged partial cross sections of the aforementioned gamma lines and compare them with available literature data. Identification of new lines and discussion of possible errors adds important value to the literature data found to be consistent with our results. In addition, for a counting time of 12 h we estimate the detection limits for cerium and chlorine as 1 and 2 mg, respectively.