The $(n,2n)$ reaction for the lightest stable erbium isotope $^{162}\mathrm{Er}$ from reaction threshold up to 19 MeV

The Er162(n,2n)Er161 reaction cross section (Eth=9.26MeV) was measured at six incident neutron beam energies by means of the activation technique. Two energy regions were covered in the present work: the near-threshold energies between 10.7 and 11.3 MeV, as well as the higher energies from 17.1 up to 19.0 MeV. In this way, the energy range from the reaction threshold up to 19 MeV was experimentally mapped, considering also the existing experimental information around 14 MeV. The quasi-monoenergetic neutron beam at near-threshold energies was produced via the H2(d,n)He3 reaction, while the higher neutron beam energies were achieved by using the H3(d,n)He4 reaction. The primary deuteron beam was delivered in both cases by the 5.5 MV Tandem Van de Graaff accelerator of NSCR “Demokritos.” Statistical model calculations were performed and compared with all the available experimental data.