Accuracy of calculation of neutron detection efficiency

The problems of the accuracy for the scintillator spectrometer calculation of neutron recording efficiency value are discussed. The calculation is performed by the method of direct simulation of neutron interaction with the scintillator substance. The preliminary calculations show that a contribution to efficiency of neutron recording in the range of energies of 10 through 50 MeV due to interaction of neutrons with carbon is mostly determined by reactions 12(in n' 2α)4He and 12(n, n' p)11B. The effciency calculation results are given for the cylindrical crystal of stilbene. Measurements of the neutron recording efficiency in the range of energies from 10 MeV indicate a good agreement between the calculation and the experiment