Neutron Total Cross Section Measurements of238U at the Fe-Filtered Neutron Energy Bands in keV Region

Abstract

The neutron total cross section of238U has been measured in the energy range from 24 keV to 1 MeV at a 100 m flight path station of the neutron time-of-flight facility of the Japan Atomic Energy Research Institute linac. Neutrons were filtered by a 30 cm-thick iron and detected by a NE-110 plastic scintillation counter. Attention was paid to taking into account the self-shielding effect below 200 keV. Fitting the measured total cross section with the average R-matrix, the neutron strength function for p- and d- wave were found to be S1×104=1.60±0.08 and S2×104=0.95±0.50, and the average distant level parameters for s- p- and d-wave to be R∞ 0=−0.081±0.005, R∞ 1=0.13±0.04, and R∞ 2=−0.01±0.68, respectively.