Measurement of neutron yields from a thick uranium target bombarded by high-energy ⁴He ions

摘要: The neutron yields induced by 500 MeV/u ⁴He ions bombarding a thick uranium target have been measured by the time-of-flight method at Heavy Ion Research Facility in Lanzhou. Simulations employing three Monte Carlo codes, GEANT4, FLUKA, and PHITS, were performed to calculate neutron yields under conditions identical to the experiment. The results indicate that all three codes reproduce key features of the experimental energy spectrum distribution to varying degrees, though each exhibits distinct advantages and limitations across specific energy intervals and spatial angles. This study provides critical data for optimizing the spallation target and subcritical reactor designs in accelerator-driven subcritical systems.