“…Several experimental data related to neutron source targets such as lithium, beryllium and carbon were measured [5,6,7,8], however, there are few data for accelerator structure material targets such as iron, aluminum, copper and others. Recently, systematic measurements of double differential thick target neutron yields (DDTTNYs) for several targets have been performed in Kyushu University [9,10,11]: carbon, titanium, cupper and niobium at 5 and 9 MeV, but aluminum only at 5 MeV. There are available DDTTNYs at 40 MeV for carbon and aluminum measured in Tohoku University [12].…”