Measurement of Neutron-Production Double-Differential Cross Sections for Intermediate Energy Pion Incident Reaction

Abstract

Neutron-production double-differential cross sections for 870-MeV π + and π − and 2.1-GeV π + mesons incident on iron and lead targets were measured with NE213 liquid scintillators by time-of-flight technique. NE213 liquid scintillators 12.7 cm in diameter and 12.7 cm thick were placed in directions of 15• , 30• , 60• , 90• , 120• and 150• . The typical flight path length was 1.5 m. Neutron detection efficiencies were derived from the calculation results of SCINFUL and CECIL codes. The experimental results were compared with the cascade-evaporation calculation code NUCLEUS. The calculation results are higher typically by a factor of two than the experimental data at neutron energies below about 30 MeV. NUCLEUS overestimates π + -incident neutron-production cross sections in forward angles at neutron energies of 100 to 500 MeV.