Cross Section Measurements of (n, n′) and (n, 2n) Reactions on Zirconium and Lead Targets at 14.8 MeV

The cross sections for the reactions 90Zr (n, n′) 90mZr, 91Zr (n, n′)2n) 90mZr, 207Pb (n, n′) 207mPb and 208Pb (n, n′)2n) 207mPb for neutron energy of 14.8 MeV have been measured by means of the activation method. The cross sections were determined with reference to the known 27A1 (n, α) 24Na reaction cross section. Isotropically enriched isotopes 90Zr, 91Zr, 207Pb and 208Pb were used as target materials. The irradiations and the activity measurements were repeated 100 times using a fast pneumatic transport system. The following cross sections were obtained: 410±40 mb for 90Zr (n, n′) 90mZr, 775±65mb for 91Zr (n, 2n) 90mZr 160±23 mb for 207Pb(n, n′) 207mPb, 1,220±100 mb for 208Pb(n, 2n) 207mPb. From the results of the present work, the effective formation cross sections of 90mZr and 207mPb for natural Zr and Pb have also been estimated as 475±40mb and 900±80mb, respectively