Affiliations: Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan | Department of Quantum Energy Engineering, Hokkaido University, Sapporo 060-8628, Japan | Center for Neutron Science, Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Ibaraki 319-1195. Japan | Department of Physics, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
Abstract: We carried out an experiment on neutron yields from typical cylindrical lead targets for 12-GeV protons by means of the Mn-bath moderation method. Our experimental results are, roughly speaking, consistent with those by Russian groups done for lower energy protons by different methods. The number of neutrons absorbed in the Mn-bath was determined to be 195 neutrons/proton, and the total neutron yield, including leakage neutrons, which were evaluated by calculations, was estimated to be 201 neutrons/proton for a 20 cm (diameter) × 60 cm (length) lead target. The total neutron yield as a function of the proton energy Ep, fitted to our data and the results of others, is expressed by the formula 2.0 + 29.2E0.78p, where Ep is expressed in GeV.
