The Physics Problem of the Spallation Neutron Production Source Related to Accelerator-driven Systems

In present work, the SHIELD code system have been used to investigate the physics properties of spallation neutron target, such as the neutron spectra, the yield, the radioactivity in the target and the target size etc. The fragment mass distribution of the residual nuclei from proton-induced spallation reaction on thick lead target with energy 1.6 GeV have been analysed also. Radiation damage, such as radiation damage cross-section, displacement atom cross-section, the rate of displacement atom, and displacement production rates in target Pb induced from intermediate energy proton and neutron incident were investigated.