Superdeformed Nuclei

Janssens, R. V. F.; Khoo, T. L.

doi:10.1146/annurev.ns.41.120191.001541

Cited by 260 publications

(145 citation statements)

References 30 publications

Supporting

Mentioning

136

Contrasting

Order By: Relevance

“…[h -2 Figure 19: Proton (π), neutron (ν), and total (t) dynamical moments of inertia in 194 Hg as a function of the rotational frequency for the SD band in 194 Hg calculated with the T22, T26, the T44, and the T62 parametrization. Experimental data are taken from [113]. Figure adapted [114] from Ref.…”

Section: Gamow-teller Statesmentioning

confidence: 99%

Tensor interaction in mean-field and density functional theory approaches to nuclear structure

Sagawa

Colò

2014

Progress in Particle and Nuclear Physics

View full text Add to dashboard Cite

The importance of the tensor force for nuclear structure has been recognized long ago. Recently, the interest for this topic has been revived by the study of the evolution of nuclear properties far from the stability line. However, in the context of the effective theories that describe medium-heavy nuclei, the role of the tensor force is still debated. This review focuses on ground-state properties like masses and deformation, on single-particle states, and on excited vibrational and rotational modes. The goal is to assess which properties, if any, can bring clear signatures of the tensor force within the mean-field or density functional theory framework. It will be concluded that, while evidences for a clear neutron-proton tensor force exist despite quantitative uncertainties, the role of the tensor force among equal particles is less well established.

show abstract

Section: Gamow-teller Statesmentioning

confidence: 99%

Tensor interaction in mean-field and density functional theory approaches to nuclear structure

Sagawa

Colò

2014

Progress in Particle and Nuclear Physics

View full text Add to dashboard Cite

show abstract

“…Heavy-ion fusion reactions have numerous applications, like the study of high spin states in yrast and super-deformed bands [1] or the formation of Heavy and Super Heavy Elements (SHE) [2]. Induced by beams of unstable nuclei, this mechanism will also allow to produce very exotic species and allow for the study of isospin equilibration in the fused system.…”

Section: Introductionmentioning

confidence: 99%

Fusion process studied with a preequilibrium giant dipole resonance in time-dependent Hartree-Fock theory

2007

View full text Add to dashboard Cite

The equilibration of macroscopic degrees of freedom during the fusion of heavy nuclei, like the charge and the shape, are studied in the Time-Dependent Hartree-Fock theory. The preequilibrium Giant Dipole Resonance (GDR) is used to probe the fusion path. It is shown that such isovector collective state is excited in N/Z asymmetric fusion and to a less extent in mass asymmetric systems. The characteristics of this GDR are governed by the structure of the fused system in its preequilibrium phase, like its deformation, rotation and vibration. In particular, we show that a lowering of the preequilibrium GDR energy is expected as compared to the statistical one. Revisiting experimental data, we extract an evidence of this lowering for the first time. We also quantify the fusion-evaporation enhancement due to γ-ray emission from the preequilibrium GDR. This cooling mechanism along the fusion path may be suitable to synthesize in the future super heavy elements using radioactive beams with strong N/Z asymmetries in the entrance channel.

show abstract

“…The nuclei having such numbers of neutrons and protons have an extra stability with respect to that expected from the average behaviour described by the liquid drop model (LDM). Many important nuclear phenomena such as the occurrence of super heavy elements [1,2], fission isomers [3,4], super-deformed nuclei [5] and new magic numbers in exotic nuclei [6,7] are the consequences of the shell effect. The shell effect also affects another fundamental property of the nucleus viz.…”

mentioning

confidence: 99%

“…A Monte Carlo calculation of the alpha-neutron coincidence spectrum reveals that the contribution from the one neutron and one proton transfer is a small fraction (< 5%) in the region of interest, even if the cross sections are the same as that of the main reaction. The most relevant reaction is the deuteron transfer followed by 5 He breakup. However, the spectroscopic factor for the d+ 5 He configuration is expected to be much smaller than the t+ 4 He configuration [22] leading to a small contribution from this reaction.…”

mentioning

confidence: 99%

Measurement of the Damping of the Nuclear Shell Effect in the Doubly MagicPb208Region

et al. 2013

View full text Add to dashboard Cite

The damping of the nuclear shell effect with excitation energy has been measured through an analysis of the neutron spectra following the triton transfer in the 7 Li induced reaction on 205 Tl.The measured neutron spectra demonstrate the expected large shell correction energy for the nuclei in the vicinity of doubly magic 208 Pb and a small value around 184 W. A quantitative extraction of the allowed values of the damping parameter γ, along with those for the asymptotic nuclear level density parameterã, has been made for the first time. The shell effect is a cornerstone of the mean field theory describing finite fermionic systems. The shell structure in atoms decides the chemical properties of the corresponding elements. In nuclear physics the spin orbit coupling, in addition, plays a dominant role in deciding the shell closures and the associated magic numbers of protons and neutrons. The nuclei having such numbers of neutrons and protons have an extra stability with respect to that expected from the average behaviour described by the liquid drop model (LDM). Many important nuclear phenomena such as the occurrence of super heavy elements [1,2], fission isomers [3,4], super-deformed nuclei [5] and new magic numbers in exotic nuclei [6,7] are the consequences of the shell effect. The shell effect also affects another fundamental property of the nucleus viz. the nuclear level density (NLD). The NLD is an indispensable input to the statistical calculation of compound nuclear decay and thus an important physical quantity for many practical applications, such as the calculations of reaction rates relevant to nuclear astrophysics, nuclear reactors and spallation neutron sources.The NLD was first calculated by Bethe using a noninteracting Fermi gas model, without shell effects, arriving at its leading dependence on excitation energy (E X ) and angular momentum (J) [8,9]. The generic behaviour with respect to E X is described by e 2 √ aE X . Here 'a' is the NLD parameter which is related to the single particle density at the Fermi energy. Direct measurements of the NLD are based on the study of slow neutron resonances, which are mainly s-and p-wave, and are extrapolated to higher J values to estimate the angular momentum summed or total NLD. The total NLD inferred from such a measurement shows that on the average the level density parameter a increases linearly with the mass number (A) of the nucleus as a ≈A/8 MeV −1 . However, there is a significant departure from this liquid drop value at shell closures. This departure is the largest for the doubly magic nucleus 208 Pb, where a (at E X ∼7 MeV) is as low as A/26 MeV −1 . This shell effect on the NLD parameter is expected to damp with excitation energy so that a approaches its liquid drop value at E X ∼ 40 MeV [10]. It is important to make measurements on the damping of the shell effect over a wide E X range. To our knowledge, no such measurement has been reported.Experimental information on the damping of the shell effect can be obtained by measuring the E X dependence...

show abstract

Superdeformed Nuclei

Cited by 260 publications

References 30 publications

Tensor interaction in mean-field and density functional theory approaches to nuclear structure

Tensor interaction in mean-field and density functional theory approaches to nuclear structure

Fusion process studied with a preequilibrium giant dipole resonance in time-dependent Hartree-Fock theory

Measurement of the Damping of the Nuclear Shell Effect in the Doubly MagicPb208Region

Contact Info

Product

Resources

About