Systematics of neutron-production cross section for proton-induced spallation reactions

The parameterization of the double differential cross section is made for the neutron emission from proton-induced spallation reaction. The neutron data for incident proton energy of 600 to 800 MeV are well analyzed by the moving source model on the basis of the Maxwell-like energy distribution. In the incident energy region below about 400 MeV, however, the use of this method leads to an unsuccessful parameterization result. Then, the Watt distribution is introduced into the moving source model in this energy region. The combination of the two distributions enables us to parameterize the double differential cross section of neutron emission for the incident protons of 25 to 800 MeV and to find the systematics of moving source model parameters for a wide variety of target nuclei. (author)