Fission Half Lives of Fermium Isotopes Within Skyrme Hartree-Fock-Bogoliubov Theory

Baran, A.; Staszczak, A.; Nazarewicz, W.

doi:10.1142/s0218301311018009

Cited by 7 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further details of the calculations can be found in Refs. [12,16,33]. Similar calculations performed for the major and minor actinides [38,39] also provide good reproduction of fission barriers and SF half-lives.…”

Section: Resultsmentioning

confidence: 61%

“…The advantage of DFT is that, while treating the nucleus as a many-body system of fermions, it identifies the essential collective degrees of freedom and provides a starting point for time-dependent extensions [29]. To describe the quantum-mechanical motion under the collective barrier, it is convenient to employ the adiabatic time-dependent HFB (ATDHFB) theory [30,31] that has been successfully applied to fission [32][33][34].…”

Section: The Modelmentioning

confidence: 99%

“…[47]. In this work, we use the perturbative HFB cranking expression for the quadrupole mass parameter B 20,20 (Q 20 ) [33,34]. The collective g.s.…”

Section: The Modelmentioning

confidence: 99%

See 2 more Smart Citations

Spontaneous fission modes and lifetimes of superheavy elements in the nuclear density functional theory

2013

Self Cite

View full text Add to dashboard Cite

Background: The reactions with the neutron-rich 48 Ca beam and actinide targets resulted in detection of new super-heavy (SH) nuclides with Z = 104 − 118. The unambiguous identification of the new isotopes, however, still poses a problem because their α-decay chains terminate by spontaneous fission (SF) before reaching the known region of the nuclear chart. The understanding of the competition between α-decay and SF channels in SH nuclei is, therefore, of crucial importance for our ability to map the SH region and assess its extent.Purpose: We perform self-consistent calculations of the competing decay modes of even-even SH isotopes with 108 ≤ Z ≤ 126 and 148 ≤ N ≤ 188. Methods:We use the state-of-the-art computational framework based on self-consistent, symmetry-unrestricted nuclear density functional theory capable of describing the competition between nuclear attraction and electrostatic repulsion. We apply the SkM* Skyrme energy density functional. The collective mass tensor of the fissioning superfluid nucleus is computed by means of the cranking approximation to the adiabatic time-dependent Hartree-Fock-Bogoliubov (HFB) approach. This work constitutes the very first systematic self-consistent study of spontaneous fission in the SH region, carried out at a full HFB level, that simultaneously takes into account both triaxiality and reflection asymmetry.Results: Breaking axial symmetry and parity turns out to be crucial for a realistic estimate of collective action; it results in lowering SF lifetimes by more than seven orders of magnitude in some cases. We predict two competing SF modes: reflection-symmetric and reflection-asymmetric. Conclusions:The shortest-lived SH isotopes decay by SF; they are expected to lie in a narrow corridor formed by 280 Hs, 284 Fl, and 284 118 Uuo that separates the regions of SH nuclei synthesized in "cold fusion" and "hot fusion" reactions. The region of long-lived SH nuclei is expected to be centered on 294 Ds with a total half-life of ∼1.5 days. Our survey provides a solid benchmark for the future improvements of self-consistent SF calculations in the region of SH nuclei.

show abstract

Section: Resultsmentioning

confidence: 61%

Section: The Modelmentioning

confidence: 99%

See 1 more Smart Citation

Spontaneous fission modes and lifetimes of superheavy elements in the nuclear density functional theory

2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…The resulting pairing strengths (in MeV fm 3 ) are V n0 = −268.9 and V p0 = −332.5. In the HF+BCS variant, we took the lowest Z (or N ) single-particle HF levels in pairing calculations with V n0 = −372.0 and V p0 = −438.0 [36].…”

Section: The Modelmentioning

confidence: 99%

Quadrupole collective inertia in nuclear fission: Cranking approximation

et al. 2011

Self Cite

View full text Add to dashboard Cite

Collective mass tensor derived from the cranking approximation to the adiabatic time-dependent Hartree-Fock-Bogoliubov (ATDHFB) approach is compared with that obtained in the Gaussian Overlap Approximation (GOA) to the generator coordinate method. Illustrative calculations are carried out for one-dimensional quadrupole fission pathways in 256 Fm. It is shown that the collective mass exhibits strong variations with the quadrupole collective coordinate. These variations are related to the changes in the intrinsic shell structure. The differences between collective inertia obtained in cranking and perturbative cranking approximations to ATDHFB, and within GOA, are discussed.

show abstract

“…Along the Fm isotope chain the barrier heights decrease rapidly with distance from N = 152, and the spontaneous fission half-lives show a similar rapid decrease, which is reproduced in numerous calculations, for example Refs. [28,[49][50][51][52][53].…”

mentioning

confidence: 99%

Fission barriers at the end of the chart of the nuclides

et al. 2015

View full text Add to dashboard Cite

We present calculated fission-barrier heights for 5239 nuclides, for all nuclei between the proton and neutron drip lines with 171 ≤ A ≤ 330. The barriers are calculated in the macroscopicmicroscopic finite-range liquid-drop model (FRLDM) with a 2002 set of macroscopic-model parameters. The saddle-point energies are determined from potential-energy surfaces based on more than five million different shapes, defined by five deformation parameters in the threequadratic-surface shape parameterization: elongation, neck diameter, left-fragment spheroidal deformation, right-fragment spheroidal deformation, and nascent-fragment mass asymmetry. The energy of the ground state is determined by calculating the lowest-energy configuration in both the Nilsson perturbed-spheroid (ǫ) and in the spherical-harmonic (β) parameterizations, including axially asymmetric deformations. The lower of the two results (correcting for zero-point motion) is defined as the ground-state energy. The effect of axial asymmetry on the inner barrier peak is calculated in the (ǫ, γ) parameterization. We have earlier benchmarked our calculated barrier heights to experimentally extracted barrier parameters and found average agreement to about one MeV for known data across the nuclear chart. Here we do additional benchmarks and investigate the qualitative, and when possible, quantitative agreement and/or consistency with data on β-delayed fission, isotope generation along prompt-neutron-capture chains in nuclear-weapons tests, and superheavy-element stability. These studies all indicate that the model is realistic at considerable distances in Z and N from the region of nuclei where its parameters were determined.

show abstract

Fission Half Lives of Fermium Isotopes Within Skyrme Hartree-Fock-Bogoliubov Theory

Cited by 7 publications

References 27 publications

Spontaneous fission modes and lifetimes of superheavy elements in the nuclear density functional theory

Spontaneous fission modes and lifetimes of superheavy elements in the nuclear density functional theory

Quadrupole collective inertia in nuclear fission: Cranking approximation

Fission barriers at the end of the chart of the nuclides

Contact Info

Product

Resources

About