The RPI multiplicity detector response to γ-ray cascades following neutron capture in 149Sm and 150Sm

The response of the RPI 16-segment NaI(Tl) multiplicity detector system to the γ-rays following neutron radiative capture reactions is discussed. An algorithm which combines the Monte-Carlo γ-cascade code DICEBOX, based on the extreme statistical model, with the general MCNP(4C) Monte-Carlo particle transport computer program is presented. Two processes, the emission of the γ-cascades accompanying the individual events of the neutron capture and the subsequent γ-ray transport through the RPI multiplicity detector were modeled. The efficiency of the RPI system for detecting neutron capture in 149,150Sm nuclei and the expected distributions of instrumental multiplicity were derived using the combined DICEBOX/MCNP(4C) code. Comparison with measured data is presented.