Measurement of neutron-production double-differential cross sections for intermediate energy pion incident reaction

Neutron-production double-differential cross sections for 870-MeV pi (+) and pi (-) and 2.1-GeV pi (+) 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 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees and 150 degrees. 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 30MeV. NUCLEUS overestimates pi (+)-incident neutron-production cross sections in forward angles at neutron energies of 100 to 500 MeV.