Neutron Capture Cross Section Measurements of Nb-93, 1-127, Ho-165, Ta-181 and U-238 between 3.2 and 80keV

The neutron capture cross sections of 93Nb, 127I, 165Ho, 181Ta and 238U were measured from 3.2 to 80 keV using the time-of-flight method. The neutron beam was produced by the KURRI 46-MeV linear accelerator and capture γ-rays were detected by a C6F6 or C6D6 liquid scintillation detector. As the result of the use of a direct-coupled operational preamplifier, the detector recovered rapidly from the γ-flash such that data for higher energy neutrons can be obtained in spite of the short flight path of 11.7 m. The neutron sensitivities of both detectors are compared and the superiority of the C6D6 detector is shown. The experimental results of capture cross sections, corrected for resonance self-shield- ing and multiple scattering and normalized to the 24-keV absolute values, are shown numerically and graphically, and compared with other data. The agreement between the data is fairly good for 165Ho and 238U, but not for 93Nb, 127I and 181Ta. The discrepancy between the data may be caused by the difference of the reference cross sections used for each experiment.