Multiple-humped fission and fusion barriers of actinide and superheavy elements

Royer, G.; Bonilla, C.

doi:10.1007/s10967-007-0507-4

Cited by 13 publications

(3 citation statements)

References 17 publications

(9 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present work it is found that the introduction of the shell and pairing energy correction, associated with touching ellipsoidal fragments, can reduce the barrier height by several MeV, even lead to a third minimum. [30] Royer et al [30,35,44] pointed out that the third minimum and third peak exist only in the asymmetric decay path and for some specific isotopes, which is in accordance with our study.…”

Section: 4 Pairing Energysupporting

confidence: 93%

Spontaneous Fission Barriers Based on a Generalized Liquid Drop Model

Guo¹,

Bao²,

Li³

et al. 2014

Commun. Theor. Phys.

View full text Add to dashboard Cite

The barrier against the spontaneous fission has been determined within the Generalized Liquid Drop Model (GLDM) including the mass and charge asymmetry, and the proximity energy. The shell correction of the spherical parent nucleus is calculated by using the Strutinsky method, and the empirical shape-dependent shell correction is employed during the deformation process. A quasi-molecular shape sequence has been defined to describe the whole process from one-body shape to two-body shape system, and a two-touching-ellipsoid is adopted when the superdeformed one-body system reaches the rupture point. On these bases the spontaneous fission barriers are systematically studied for nuclei from 230Th to 249Cm for different possible exiting channels with the different mass and charge asymmetries. The double, and triple bumps are found in the fission potential energy in this region, which roughly agree with the experimental results. It is found that at around Sn-like fragment the outer fission barriers are lower, while the partner of the Sn-like fragment is in the range near 108Ru where the ground-state mass is lowered by allowing axially symmetric shapes. The preferable fission channels are distinctly pronounced, which should be corresponding to the fragment mass distributions.

show abstract

Section: 4 Pairing Energysupporting

confidence: 93%

Spontaneous Fission Barriers Based on a Generalized Liquid Drop Model

Guo¹,

Bao²,

Li³

et al. 2014

Commun. Theor. Phys.

View full text Add to dashboard Cite

show abstract

“…During the last years, the efforts for developing improved models for the calculation of fission barriers were intensified, using the macroscopic-microscopic approach [27,[39][40][41][42][43][44], the density-functional theory [22,45,46] and varieties of Hartree-Fock methods [47][48][49][50]. Still, the results from the different models, in particular in regions, where no experimental data exist, differ appreciably.…”

Section: A Systematics Of Fission Barriersmentioning

confidence: 99%

General Description of Fission Observables: GEF Model Code

Schmidt

Jurado

Amouroux

et al. 2016

Nuclear Data Sheets

426

421

View full text Add to dashboard Cite

The GEF ("GEneral description of Fission observables") model code is documented. It describes the observables for spontaneous fission, neutron-induced fission and, more generally, for fission of a compound nucleus from any other entrance channel, with given excitation energy and angular momentum. The GEF model is applicable for a wide range of isotopes from Z = 80 to Z = 112 and beyond, up to excitation energies of about 100 MeV. The results of the GEF model are compared with fission barriers, fission probabilities, fission-fragment mass-and nuclide distributions, isomeric ratios, total kinetic energies, and prompt-neutron and prompt-gamma yields and energy spectra from neutron-induced and spontaneous fission. Derived properties of delayed neutrons and decay heat are also considered.The GEF model is based on a general approach to nuclear fission that explains a great part of the complex appearance of fission observables on the basis of fundamental laws of physics and general properties of microscopic systems and mathematical objects. The topographic theorem is used to estimate the fission-barrier heights from theoretical macroscopic saddle-point and ground-state masses and experimental ground-state masses. Motivated by the theoretically predicted early localisation of nucleonic wave functions in a necked-in shape, the properties of the relevant fragment shells are extracted. These are used to determine the depths and the widths of the fission valleys corresponding to the different fission channels and to describe the fission-fragment distributions and deformations at scission by a statistical approach. A modified composite nuclear-level-density formula is proposed. It respects some features in the superfluid regime that are in accordance with new experimental findings and with theoretical expectations. These are a constant-temperature behaviour that is consistent with a considerably increased heat capacity and an increased pairing condensation energy that is consistent with the collective enhancement of the level density. The exchange of excitation energy and nucleons between the nascent fragments on the way from saddle to scission is estimated according to statistical mechanics. As a result, excitation energy and unpaired nucleons are predominantly transferred to the heavy fragment in the superfluid regime. This description reproduces some rather peculiar observed features of the prompt-neutron multiplicities and of the even-odd effect in fission-fragment Z distributions. For completeness, some conventional descriptions are used for calculating pre-equilibrium emission, fission probabilities and statistical emission of neutrons and gamma radiation from the excited fragments. Preference is given to simple models that can also be applied to exotic nuclei compared to more sophisticated models that need precise empirical input of nuclear properties, e.g. spectroscopic information.The approach reveals a high degree of regularity and provides a considerable insight into the physics of the fission process. Fission obs...

show abstract

“…Forced fission of isotopes of heavy mass elements by interaction with thermal neutrons is a complex and multi-factor process. In studying this process, many authors have aimed at developing and describing the fission mechanism [1][2][3][4][5][6][7][8][9][10][11][12][13], sets of the most probable fission fragments [14][15][16][17][18][19] and elementary particles [20][21][22], and total energy balance [23][24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Fission Mechanism of 235U+n Reaction According to the Symmetrical Atomic Nucleus Model

Denisov

Razinkin

Atuchin

2022

Atoms

View full text Add to dashboard Cite

In this study, the variants of structures are considered for fission fragments of the 235U nucleus caused by thermal neutrons, depending on differences in the initial configuration of proton, neutron and alpha particle compositions, according to a symmetrical model developed for the atomic nucleus. The proposed model is based on the principles of spatial symmetry and the analysis of the binding energy of the nucleus, taking into account the quark structure of nucleons. For the first time, the number of alpha particles in the composition of the 235U nucleus is considered to be 44 and the total number of connections between nucleons is 292. The work compares the binding energy of fragments of the atomic nucleus 235U, which have the same number of protons and neutrons in their composition, but a different number of alpha particles. The results obtained are the basis for an experimental study on the energy characteristics of various fission options of the 235U+n reaction, which is of interest for improving the efficiency of nuclear power sources.

show abstract

Multiple-humped fission and fusion barriers of actinide and superheavy elements

Cited by 13 publications

References 17 publications

Spontaneous Fission Barriers Based on a Generalized Liquid Drop Model

Spontaneous Fission Barriers Based on a Generalized Liquid Drop Model

General Description of Fission Observables: GEF Model Code

Fission Mechanism of 235U+n Reaction According to the Symmetrical Atomic Nucleus Model

Contact Info

Product

Resources

About