Neutron capture cross section measurements of 151,153Eu using a pair of C6D6 detectors

We have measured the neutron capture cross sections of Eu-151 and Eu-153 by the time-of-flight (TOF) method in the range from 0.005eV to keV region using the Kyoto University Research Reactor Institute - Linear Accelerator (KURRI-LINAC). We employed a pair of C6D6 liquid scintillators for the prompt capture -ray measurement. The pulse-height weighting technique was employed to obtain the capture yields from the -ray spectra of Eu-151,Eu-153. The obtained thermal cross sections at 0.0253eV are 9051 683 b for Eu-151 and 364 +/- 44 b for Eu-153, respectively. The resonance integrals have been derived as 3490 +/- 162 b for Eu-151 and 1538 +/- 106 b for Eu-153.The obtained capture cross sections were compared with the previously reported experimental data and the evaluated data. The evaluated data in JENDL-4.0 and JEFF-3.2 show good agreement with the present experiment results of Eu-151, however, the evaluated data in ENDF/B-VII.1 are larger than the present experiment results of Eu-151 about 10% to 20% in the energy region from 0.03 to 0.2eV. For the neutron capture cross sections of Eu-153, the evaluated data in ENDF/B-VII.1 and Widder's data are in good agreement with the present results in the energy region below 0.35 eV.