Study of neutron detection efficiencies for liquid organic scintillator up to 3 GeV

The Monte Carlo code, designated SCINFUL-QMD, is developed to calculate the neutron detection efficiency up to 3 GeV for liquid organic scintillator such as NE-213. The existing Monte Carlo code, SCINFUL, is known to reproduce the response function and detection efficiency at incident neutron energies below 80 MeV. We incorporate the quantum molecular dynamics plus statistical decay model (QMD+SDM) into SCINFUL to extend the upper limit of incident neutron energy to 3 GeV. The tabulated cross sections adopted in SCINFUL are extrapolated up to 150 MeV, and the QMD+SDM method is used above 150 MeV. The results of SCINFUL-QMD are compared with the experimental data and those of another computation code CECIL. At lower energies below 20 MeV, the results of SCINFUL-QMD agree with the experimental data. At higher energies, this code gives small values than the experimental data. SCINFUL-QMD exhibits the increase in detection efficiency above 300 MeV. This result is achieved by taking charged pion production into account.