Study of low-lying states in151Eu via (n,n′γ) reaction

The levels of¹⁵¹Eu have been investigated in the (n,n′γ) reaction using nuclear reactor fast neutrons. The energies, intensities and angular distributions of theγ-rays have been measured with the Ge(Li) spectrometer. Four rotational bands with the following band heads and Nilsson configurations have been identified: ground state band, 5/2⁺ 402]; 21.5 keV, 7/2⁺404]; 196.5 keV, 3/2⁺411]; 260.5 keV, 5/2⁺413]. The low spin states at 332.2 and 336.2 keV have been tentatively assigned to the l/2⁺411] Nilsson orbital, but 522.8, 580.0 and 587.0 keV states to the 1/2⁺420] Nilsson orbital. The negative parity levels at 353.7, 522.1 and probably 546.2 keV have been proposed basing on theh _11/2 proton state.