Higher Order Corrections to the Cranking Model

A spectroscopic investigation of the γ decays from excited states in 159 Er has been performed in order to study the changing structural properties exhibited as ultrahigh spins (I > 60h) are approached. The nucleus 159 Er was populated by the reaction 116 Cd( 48 Ca,5nγ) at a beam energy of 215 MeV and the resulting γ decays were studied using the Gammasphere spectrometer. New rotational bands and extensions to existing sequences were observed, which are discussed in terms of the cranked shell model, revealing a diverse range of quasiparticle configurations. At spins around 50h there is evidence for a change from dominant prolate collective motion at the yrast line to oblate non-collective structures via the mechanism of band termination. A possible strongly deformed triaxial band occurs at these high spins, which indicates collectivity beyond 50h. The high spin data are interpreted within the framework of cranked Nilsson-Strutinsky calculations.

Section: Discussionmentioning

confidence: 99%

Diverse collective excitations in159Erup to high spin

Mustafa¹,

Ollier²,

Simpson³

et al. 2011

“…The energy of the 2 + 1 state of 158 Nd can be estimated from an examination of the kinematic moments of inertia, J (1) = 2 (2I − 1)/E γ , derived from the energies of the 6 + → 4 + and 4 + → 2 + transitions. These then allow the ground-state rotational band to be quantified in terms of the Harris parameters [16] …”

Section: Resultsmentioning

confidence: 99%

μs isomers of Nd158,160

Ideguchi¹,

Simpson²,

Yokoyama³

et al. 2016

“…In order to extrapolate the unobserved transition energies, the same procedure was used as in e.g. [3,34] of parameterising the kinematic (J (1) ) and dynamic (J (2) ) moments of inertia of the rotational band according to the Harris formalism [35], where…”

Section: B Excitation Functionsmentioning

confidence: 99%

In-beam spectroscopic study of Cf244

Konki¹,

Sulignano²,

Greenlees³

et al. 2018

The ground-state rotational band of the neutron-deficient californium (Z = 98) isotope 244 Cf was identified for the first time and measured up to a tentative spin and parity of I π = 20 + . The observation of the rotational band indicates that the nucleus is deformed. The kinematic and dynamic moments of inertia were deduced from the measured γ-ray transition energies. The behaviour of the dynamic moment of inertia revealed an up-bend due to a possible alignment of coupled nucleons in high-j orbitals starting at a rotational frequency of abouthω = 0.20 MeV. The results were compared to the systematic behaviour of the even-even N = 146 isotones as well as to available theoretical calculations that have been performed for nuclei in the region.