Evaluation of neutron inelastic scattering for radioisotope production

A systematic study of the production of 117mSn, 119mSn and 195mPt in the hydraulic tube facility (HT) of the ORNL High Flux Isotope Reactor (HFIR) has demonstrated that in all three cases the yields from neutron inelastic scattering (AZ[n,n′] AmZ) were higher than yields obtained from neutron capture reactions ((A−1)Z[n,γ]AmZ). The corresponding fission-averaged cross-sections were 222 ± 16, 168 ± 12 and 287 ± 20 mb, respectively. The relative gains in the specific activity were 1.4 for 195mPt, 3.3 for 117mSn and 4.4 for 119mSn. The larger gain from 119mSn could be attributed to the relatively lower excitation energy (89.5 keV) of this metastable nucleus. As a part of these studies, the thermal neutron capture cross-sections and resonance integrals for the above reactions and the cross-sections for the [n,2n] reactions leading to the above nuclides were also evaluated.