High Energy Neutron Activation Cross Sections

Abstract

A systematic study on neutron activation cross-section measurements in the energy from 20 MeV to 150 MeV has been performed over several years. For this study, we have developed the quasi-monoenergetic neutron fields using 7Li(p, n) reaction at three AVF cyclotron facilities; 1) Institute for Nuclear Study, University of Tokyo for 20 to 40 MeV protons, 2) Takasald Institute of Advanced Radiation Applications(TIARA) of Japan Atomic Energy Research Institute(JAERI) for 40 to 90 MeV protons, 3) Institute of Physical and Chemical Research(RIKEN) for 70 to 210 MeV protons. By using these neutron fields, we have measured the activation cross sections of 30Si(n, np), 47Ti(n, np), 48Ti(n, np), 52Cr(n, 2n), 58Ni(n, 2n) in the energy range of 15 to 40 MeV, and of 12C(n, 2n), 59Co(n, xn) and (n, xnp), natCu(n, xn) and (n, xnp), 209Bi(n, xn) in the energy range of 15 to 80 or 150 MeV. We are now developing a new p-Li quasi-monoenergetic neutron field in the energy range of 20 to 90 MeV using a new AVF cyclotron installed in the Cyclotron and Radioisotope Center, Tohoku University, for measurements of neutron activation cross sections of light elements such as O and N which are included in air, water and soil.