Measurements of double differential neutron production cross sections by 135 MeV/nucleon He, C, Ne and 95 MeV/nucleon Ar ions

Abstract

The double differential cross sections of neutron production from thin C, Al, Cu, and Pb targets bombarded by 135 MeV/nucleon He, C, and Ne ions and by 95 MeV/nucleon Ar ion were measured using the RIKEN Ring Cyclotron of the Institute of Physical and Chemical Research, Japan. The neutron energy spectra at 0\ifmmode^\circ\else\textdegree\fi{}, 15\ifmmode^\circ\else\textdegree\fi{}, 30\ifmmode^\circ\else\textdegree\fi{}, 50\ifmmode^\circ\else\textdegree\fi{}, 80\ifmmode^\circ\else\textdegree\fi{}, and 110\ifmmode^\circ\else\textdegree\fi{} were obtained by using the time-of-flight method. The neutron spectra in the forward direction have a sharp peak that is located at the incident particle energy per nucleon due to the knockon process, and spreads out to about three times the incident particle energy per nucleon. The resultant spectra were integrated over energy to produce neutron angular distributions. The total neutron production cross sections were obtained by integrating over the angular distributions. The experimental results are compared with calculations using the intranuclear cascade-evaporation Monte Carlo code HIC and the quantum molecular dynamics code QMD.