JAEA-Conf 2011-002 - 日本原子力研究開発機構

in this work was confirmed.
(2) 153 Eu
The preliminary neutron capture cross sections of 153 Eu were obtained in the neutron energy
region from 0.03 eV to 4 keV as shown in Fig. 5. Widder measured the capture cross sections in the
region from 0.01 to 10 eV, using a reactor with a fast chopper [6]. The results of Widder are larger than
the present results by about 20 % in the thermal energy region. On the other hand, the evaluated values
of JENDL-4.0 show good agreement with the present ones below 1 eV. In the energy range from 100
eV to 4 keV, the present data agree well with the experimental data by Konks et al.[7] and Moxon et
al.[8], while the discrepancy between the evaluated values of JENDL-4.0 and the present results
ranges from 5 to 40 %. An undesirable structure is clearly observed around 0.6 eV. There is a
possibility that the correction for 151 Eu as an isotopic impurity was not completely made.
5. Conclusion
The preliminary neutron capture cross sections of 151 Eu and 153 Eu have been measured from
0.03 eV to the keV region with a pair of C6D6 detectors by the TOF method. As for 151 Eu, the present
data agree well with the previous experimental data and the evaluated values of JENDL-4.0. Therefore,
the validity of the weighting function derived in this work was confirmed. As for 153 Eu, the results of
Widder are larger than the presents by about 20 % at the thermal energy. The evaluated values of
JENDL-4.0 are in good agreement with the present ones except the energy region from 100 eV to 4
keV.
Acknowledgement
The authors would like to express their thanks to the linac staff of the KURRI for making it
possible to operate the accelerator steadily. They would also like to express their thanks to Dr. Takumi
Kubota for cooperation on calculation with the EGS5, and to Prof. Samyol Lee and Mr. Naoya Abe for
their helpful discussions.
Counts / 25keV / γ-ray
JAEA-Conf 2011-002
γ-ray Energy (MeV)
Fig. 2. Simulated response function of a pair of C6D6 liquid scintillators