1 Risø National Laboratory, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2 Risø National Laboratory for Sustainable Energy, Technical University of Denmark
Theγ-ray spectrometer at the DR 3-reactor at Risø was used to investigate the low energyγ-lines of U 239 which are emitted during neutron-capture in U 238. Very closely lying lines have been found between 500 and 650 keV. The big intensity of the 133 keV line and the lack of other transitions of appropriate energy and intensity point out that this line corresponds to the hinderedE 2-transition from the (631)I=1/2+ level to the (622)I=5/2+ groundstate. A suggestion was made for the decay possibility of the octupole states at 700 keV found by N.Fiebiger.
Zeitschrift Für Physik, 1965, Vol 184, Issue 2, p. 143-152