Neutron Productions from thin Be target irradiated by 50 MeV/u U-238 beam

Neutrons generated from thin beryllium target by 50 MeV/u U-238 beam were measured using activation analysis at 15, 30, 45, and 90 degrees from the beam direction. A 0.085 mm-thick Be stripper of RIBF was used as the neutron generating target. Activation detectors of bismuth, cobalt, and aluminum were placed out of the stripper chamber. The threshold reactions of Bi-209(n, xn)Bi210-x(x=4 similar to 8), Co-59(n, xn)60-xCO(x=2 similar to 5), Co-59(n, 2n alpha)Mn-54, Al-27(n, alpha)Na-24, and Al-27(n,2n alpha)Na-22 were applied to measure the production rates ofradionuclides. The neutron spectra were obtained using an unfolding method with the SAND-II code. All of production rates and neutron spectra were compared with the calculated results using Monte Carlo codes, the PHITS and the FLUKA. The FLUKA results showed better agreement with the measurements than the PHITS. The discrepancy between the measurements and the calculations were discussed.