Study of¹⁵¹Eu levels via the (p,2nγ) reaction

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

“…The higher energy component evidently depopulates the 697.4 keV level. The 303 and 482keV transitions have also double assignments which is evident from the different intensities in [11,23] and in our measurements.…”

“…Hence we conclude that in the 151Gd decay the levels 5/2 + and 9/2 + at about 307 keV are not populated, and, according to the data of [183 is populated only the 7/2 + level with the excitation energy 307.521 keV. Our data as well as those of [10,11,23] do not agree with the existence of the transition 284.721 keV, see [18]. This considerably reduces the probability that there exists one more level [18] at 306.226 keV.…”

“…Multiple neutron scattering in the target could be neglected in our case because the target was rather thin. The transition intensities were normalized to the intensity of the i74 keV line in order to obtain a good scale for a comparison with the data [11] of the (p, 2n ?) reaction.…”

“…On the other hand the last measurements of the ~51Gd decay [18] have yielded the value 286.098 +0.014keV. Besides, the analysis of the existing data indicates that the 110.51 keV transition from the tS~Gd decay is not identical to the 110.7 keV transition which has been observed in the reaction experiments [10,11]. Hence we conclude that in the 151Gd decay the levels 5/2 + and 9/2 + at about 307 keV are not populated, and, according to the data of [183 is populated only the 7/2 + level with the excitation energy 307.521 keV.…”

“…This level has been proposed in a paper [11] on the basis of the strong coincidence 139. 7-196.5keV 139.7keV transition has been nearly isotropic, and this fact has excluded the pure multipolarity E2 or El.…”