Measurements of Double Differential Cross Sections at OKTAVIAN

Abstract

This is a brief review of the measurements of double differential neutron emission cross sections, which have been done at the OKTAVIAN facility of Osaka University since 1981, for many elements of fusion reactor materials. In the phase-1 experiments, double differential cross sections with high energy resolution and good counting satisfies were accumulated for D, Li, Be, B, C, N, O, F, Na, Al, Si, CI, Ti, Cr, Mn, Fe, Ni, Cu, Zr, Nb, Mo, W and Pb. The ring geometry TOF spectrometer was used in the phase-1, a drawback of which was due to the considerable variation of incident energy. In the phase-2 experiments, a new TOF spectrometer was installed for fixing the incident neutron energy to be 14.1 MeV and keeping the energy resolution and counting statistics. We can then obtain angle-integrated emission spectra and partial differential cross sections from measured double differential neutron emission cross sections. In the phase-2, measurements have been done for Be, C, 10B, 11B, F, Mg, Al, Si, V, Cr, Fe, Ni, Cu, Pb and Bi. All the data in the two phases have been efficiently utilized to improve evaluated neutron cross sections in JENDL-3, EFF-l and ENDF/B-VI.