Measurement of Neutron Production Cross Sections by High-Energy Heavy Ions

Abstract

The double-differential cross sections (DDX) of neutron production by high energy heavy ions were measured using the RIKEN Ring Cyclotron of the Institute of Physical and Chemical Research, Japan, and the Heavy Ion Medical Accelerator in Chiba (HIMAC), the National Institute of Radiological Sciences. The neutron energy spectra from 0 to 110 degrees were obtained by using the time-of-flight method. The neutron spectra in the forward direction have a sharp peak which is located at the incident particle energy per nucleon due to the knock-on process, and spreads out to about 3 times the incident particle energy per nucleon. The total neutron production cross sections were obtained by integrating the energy spectra above 20 MeV over a hemisphere from 0 to 90 degrees. The experimental results are compared with calculations using the intranuclear cascade-evaporation Monte Carlo code, HIC, and the quantum molecular dynamics code, QMD. The QMD codes give better agreement with the experimental results than the HIC code.