Uncertainties of DS86 and Prospects for Residual Radioactivity Measurement

Abstract

Residual radioactivity data of ¹⁵²Eu, ⁶⁰Co and ³⁶Cl have been accumulated and it has been revealed in the thermal neutron region that a systematic discrepancy exists between the measured data and activation calculation based on the DS86 neutrons in Hiroshima. Recently ⁶³Ni produced in copper samples by the fast neutron reaction ⁶³Cu(n,p) ⁶³Ni has been of interest for evaluation of fast neutrons. Reevaluation of atomic-bomb neutrons and prospects based on residual activity measurements have been discussed.