We have investigated the energy response of a 6 Li-loaded liquid scintillator to MeV neutrons. It consists of three 6 Li-glass scintillator plates inside a liquid organic scintillator BC-501A, which can detect selectively neutrons that lose the full energy in the BC-501A using a coincidence signal generated from the capture event of thermalized neutrons in the 6 Li-glass scintillators. The response functions were measured using 4.7, 7.2 and 9.0 MeV monoenergetic neutrons. The measured ones were compared with Monte Carlo calculations performed by combining the neutron transport code PHITS and the scintillator response calculation code SCINFUL. The experimental light output spectra were in good agreement with the calculated ones in shape. The energy dependence of the detection efficiency was reproduced by the calculation.

Abstract. The PHITS code is applied to neutronic calculations for the high flux test module in IFMIF. The neutron energy spectrum and heating rate calculated with the Li(d,xn) neutron source term obtained by the McDelicious code reproduce the FZK result fairly well. The sensitivity of three nuclear data libraries (LA150, NRG-2003, and JENDL/HE-2004) to nuclear heating calculation and the validity of KERMA approximation are discussed. A new nuclear data evaluation of the d + Li reaction is proposed on the basis of an advanced model calculation with a continuum-discretized coupled-channels (CDCC) method. A preliminary CDCC analysis of deuteron elastic scattering from Li is presented.

Characteristics of a (6)Li-loaded neutron coincidence spectrometer were investigated from both measurements and Monte Carlo simulations. The spectrometer consists of three (6)Li-glass scintillators embedded in a liquid organic scintillator BC-501A, which can detect selectively neutrons that deposit the total energy in the BC-501A using a coincidence signal generated from the capture event of thermalised neutrons in the (6)Li-glass scintillators. The relative efficiency and the energy response were measured using 4.7, 7.2 and 9.0 MeV monoenergetic neutrons. The measured ones were compared with the Monte Carlo calculations performed by combining the neutron transport code PHITS and the scintillator response calculation code SCINFUL. The experimental light output spectra were in good agreement with the calculated ones in shape. The energy dependence of the detection efficiency was reproduced by the calculation. The response matrices for 1-10 MeV neutrons were finally obtained.