Averaged cross sections for the reactions (68)Zn(n,p)(68g)Cu and (68)Zn(n,p)(68m)Cu for a (235)U fission neutron spectrum.

摘要

Making use of the method developed in our laboratory for the simultaneous determination of cross sections leading to both the ground and metastable states, we have measured the (68)Zn(n,p)(68g)Cu and (68)Zn(n,p)(68m)Cu reactions, using Zn enriched to 99.4% in its isotope (68)Zn. The measured cross sections are (15.04+/-0.35) and (3.69+/-0.30)mub for the ground and metastable state, respectively. However, a direct determination of the cross section leading to the metastable state gives a value of (4.75+/-0.38)mub. A possible reason for this discrepancy-which is outside experimental uncertainties-is that some tabulated values used in our calculations for the decay parameters of (68g)Cu and (68m)Cu, have either larger than quoted, or unknown systematic, uncertainties.