Preliminary measurement of neutron emission spectra for beryllium at 21.65 MeV neutrons

The neutron emission spectra were measured for the neutron induced reactions on beryllium at incident energy of 21.65 MeV using time-of-flight techniques. The measured TOF spectra were analyzed by detailed Monte-Carlo simulation and the cross sections were determined by comparing the measured TOF spectra with simulated ones. The cross sections were normalized to n-p scattering measurement. This paper gives the preliminary results of the elastic scattering angular distributions and part of the secondary neutron emission double-differential cross sections (DDXs). A theoretical model based on the Hauser-Feshbach and exciton model for light nuclei was used to describe the double-differential cross sections of n+9Be. The experimental data were compared with the results of calculation and other measurements. (author)