Rotational bands in odd-ACm and Cf isotopes: Exploring the highest neutron orbitals

Population and decay of aKπ=8−two-quasineutron isomer inPu244

“…However, previous measurements using transient magnetic fields [30] have shown that the value of g R is ≈ 0.8*Z/A (∼0.31) for 232 Th and 238 U, in agreement with the choice in Ref. [29]. Although similar measurements are not available for heavier actinide nuclei, a range of values for g R have been explored, (Z = 94) to No (Z = 102) [13] is a clear indication of a pure neutron contribution.…”

“…Experimentally extracted |(g K − g R )/Q 0 | values, using Q 0 = 12 eb [29] and an attenuation of 0.6 for the intrinsic spin g factors, are compared with expectations for three different low-lying 2-qp configurations (Fig.4). In the literature, g R values used in this region vary, from 0.31 for the odd-A Cm and Cf isotopes [29], to g R = Z/A = 0.4 for 250 Fm [12].…”

“…In the literature, g R values used in this region vary, from 0.31 for the odd-A Cm and Cf isotopes [29], to g R = Z/A = 0.4 for 250 Fm [12]. However, previous measurements using transient magnetic fields [30] have shown that the value of g R is ≈ 0.8*Z/A (∼0.31) for 232 Th and 238 U, in agreement with the choice in Ref.…”

Towards Superheavies: Spectroscopy of 94 < Z < 98, 150 < N < 154 Nuclei

“…A comparison of the alignment behaviour of 251 Cf with its neighbouring lighter N = 153 isotone 249 Cm [9] shows that the two align at frequencies that differ by ≈0.03 MeV, precluding a neutron alignment scenario and endorsing a proton alignment behaviour for both nuclei.…”

“…This is the first time high-spin rotational bands built on both ground and excited state configurations, especially on orbitals other than the j 15/2 neutron orbital, have been identified and characterised in N > 150 systems. A longstanding unresolved issue in the A ∼ 250 region is the fact that the expected early alignment of the j 15/2 neutrons from cranked Woods-Saxon predictions is not observed [9,10], while the alignment of i 13/2 protons, typically predicted to occur at frequencies higher than the neutrons, has been fully mapped, e.g, in 244 Pu [4]. The identification of collective bands built on different configurations in the N = 151 isotones of Pu, Cm and Cf now allow competing alignment contributions from neutrons and protons to be disentangled using blocking arguments [6].…”