International Conference on Nuclear Data for Science and Technology 2007
DOI: 10.1051/ndata:07185

Search for isomeric transitions in fission products around mass number 150

Y. Kojima¹, M. Shibata², A. Taniguchi³, A. Murataka¹, K. Ota¹ and K. Shizuma<sup>1

1</sup>  Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
²  Radioisotope Research Center, Nagoya University, Nagoya 464-8602, Japan
³  Research Reactor Institute, Kyoto University, Kumatori 590-0494, Japan

ykojima@hiroshima-u.ac.jp

Published online: 21 May 2008

Abstract
A β-gated γ-ray and internal conversion electron measurement system for identifying isomers has been installed to the isotope separator on-line at the Kyoto University Research Reactor. On-line measurements for mass number A = 93 nuclides clearly showed that it had sufficient ability to distinguish isomeric transitions from those following β-decay. Using this equipment, an isomeric state in ¹⁴⁸Pr was successfully observed at 76.8 keV, and one in ¹⁵¹Pr at 35.1 keV. We also found a candidate of an isomeric transition in an A =150 nuclide produced by the thermal neutron-induced fission of ²³⁵U.

© CEA 2008