Measurements of neutron-induced neutron-production double-differential cross sections from 50 to 150 MeV

We measured neutron-production double-differential cross-sections by neutron incidence from 50 to 150 MeV. A ²³⁸U fission ionization chamber was set to take the incident-neutron flux. Six NE213 liquid scintillators which had a thickness of 12.7 cm and 12.7 cm in diameter, were placed at 15°, 30°, 60°, 90°, 120°, and 150° to detect neutrons emitted from a sample. The energy of incident neutron was determined by the time of flight (TOF) technique. The energy spectra of neutron emitted from the sample were derived by the unfolding their light output spectra with the response functions of the detectors. The response functions were measured with the spallation neutrons above 25 MeV. In the unfolding process, we assumed that neutron energy spectra reproduced the shape by the moving source model. The neutron-induced neutron-production double-differential cross sections were parameterized with the moving source model by the least-square method. The experimental results were compared with calculations of the PHITS and the TALYS codes.