Analysis of Lithium Fluoride γ-ray Production Cross Sections*

The ⁷Li and ¹⁹F nuclei were studied at the University of Kentucky Accelerator Laboratory using neutron inelastic scattering. The research focused on the detection of γ-rays produced when the excited nucleus, formed from the inelastic collision, returned to a lower energy state. The deduced γ-ray production cross sections were then used to determine neutron inelastic scattering cross sections. The Van de Graaff accelerator at UKAL was used to produce a pulsed beam of protons, which then produced neutrons in one of two secondary reactions: ²H(p,n)³He or ²H(d,n)³He. γ-ray excitation functions were measured following the (n,n´γ) reaction for incident neutron energies from 0.8 MeV to 4.5 MeV with the germanium detector fixed at 125˚. The excitation functions were normalized absolutely by analogous measurements on nat-Ti using well-known neutron cross sections. The importance of these measurements results from (a) the ¹⁹F neutron inelastic cross sections are used in modeling fuel processing and fuel recycling in fusion reactor systems and (b) the ⁷Li cross sections are used in the cooling system for light water reactors.