Journal ArticleDOI
Heavy-element fission barriers
Peter Möller,Arnold J. Sierk,Takatoshi Ichikawa,Akira Iwamoto,Ragnar Bengtsson,Henrik Uhrenholt,Sven Åberg +6 more
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In this paper, the authors presented calculations of fission properties for heavy elements based on the macroscopic-microscopic finite-range liquid-drop model with a 2002 parameter set.Abstract:
We present calculations of fission properties for heavy elements. The calculations are based on the macroscopic-microscopic finite-range liquid-drop model with a 2002 parameter set. For each nucleus we have calculated the potential energy in three different shape parametrizations: (1) for 5 009 325 different shapes in a five-dimensional deformation space given by the three-quadratic-surface parametrization, (2) for 10 850 different shapes in a three-dimensional deformation space spanned by epsilon(2), epsilon(4), and gamma in the Nilsson perturbed-spheroid parametrization, supplemented by a densely spaced grid in epsilon(2), epsilon(3), epsilon(4), and epsilon(6) for axially symmetric deformations in the neighborhood of the ground state, and (3) an axially symmetric multipole expansion of the shape of the nuclear surface using beta(2), beta(3), beta(4), and beta(6) for intermediate deformations. For a fissioning system, it is always possible to define uniquely one saddle or fission threshold on the optimum trajectory between the ground state and separated fission fragments. We present such calculated barrier heights for 1585 nuclei from Z=78 to Z=125. Traditionally, actinide barriers have been characterized in terms of a "double-humped" structure. Following this custom we present calculated energies of the first peak, second minimum, and second peak in the barrier for 135 actinide nuclei from Th to Es. However, for some of these nuclei which exhibit a more complex barrier structure, there is no unique way to extract a double-humped structure from the calculations. We give examples of such more complex structures, in particular the structure of the outer barrier region near Th-232 and the occurrence of multiple fission modes. Because our complete results are too extensive to present in a paper of this type, our aim here is limited: (1) to fully present our model and the methods for determining the structure of the potential-energy surface, (2) to present fission thresholds for a large number of heavy elements, (3) to compare our results with the two-humped barrier structure deduced from experiment for actinide nuclei, and (4) to compare to additional fission-related data and other fission models. . (Less)read more
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RIPL – Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations
Roberto Capote,M.W. Herman,M.W. Herman,P. Obložinský,P. Obložinský,Phillip G. Young,Stéphane Goriely,Tamás Belgya,A.V. Ignatyuk,Arjan J. Koning,Stéphane Hilaire,Vladimir Plujko,Marilena Avrigeanu,O. Bersillon,Mark B. Chadwick,Tokio Fukahori,Zhigang Ge,Yinlu Han,S. Kailas,J. Kopecky,V.M. Maslov,G Reffo,M. Sin,E. Sh. Soukhovitskii,Patrick Talou +24 more
TL;DR: The Reference Input Parameter Library (RIPL-3) as mentioned in this paper is a library of validated nuclear-model input parameters, referred to as the RIPL-2 library, which has been used extensively in the development and use of nuclear reaction modelling.
Journal ArticleDOI
Nuclear ground-state masses and deformations: FRDM(2012)
TL;DR: In this article, the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground state microscopic corrections, and nuclear ground state deformations of 9318 nuclei ranging from 16O to A = 339 were tabulated.
Journal ArticleDOI
General Description of Fission Observables: GEF Model Code
TL;DR: The GEF model as discussed by the authors 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.
Journal ArticleDOI
Nuclear energy density optimization: Large deformations
M. Kortelainen,M. Kortelainen,J. McDonnell,J. McDonnell,Witold Nazarewicz,Witold Nazarewicz,Witold Nazarewicz,Paul-Gerhard Reinhard,Jason Sarich,Nicolas Schunck,Nicolas Schunck,Nicolas Schunck,Mario Stoitsov,Mario Stoitsov,Stefan M. Wild +14 more
TL;DR: In this paper, a new Skyrme-like energy density suitable for studies of strongly elongated nuclei has been determined in the framework of the Hartree-Fock-Bogoliubov theory using the recently developed model-based, derivative-free optimization algorithm POUNDerS.
Journal ArticleDOI
Radioactive decays at limits of nuclear stability
TL;DR: A review of the decay modes occurring close to the limits of stability is presented in this paper, where the experimental methods used to produce, identify, and detect new species and their radiation are discussed.
References
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Journal ArticleDOI
Watersheds in digital spaces: an efficient algorithm based on immersion simulations
Luc Vincent,Pierre Soille +1 more
TL;DR: A fast and flexible algorithm for computing watersheds in digital gray-scale images is introduced, based on an immersion process analogy, which is reported to be faster than any other watershed algorithm.
Journal ArticleDOI
Nuclear ground state masses and deformations
TL;DR: In this paper, the atomic mass excesses and nuclear ground-state deformations of 8979 nuclei ranging from 16O to A = 339 were tabulated based on the finite-range droplet macroscopic model and the folded-Yukawa single-particle microscopic model.
Journal ArticleDOI
ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology
Mark B. Chadwick,P. Obložinský,M.W. Herman,N.M. Greene,R.D. McKnight,David Livingstone Smith,Phillip G. Young,R. E. MacFarlane,Gerald M. Hale,S.C. Frankle,A.C. Kahler,Toshihiko Kawano,R. C. Little,D. G. Madland,Peter Möller,Russell D. Mosteller,Philip R. Page,Patrick Talou,Holly R. Trellue,Morgan C. White,William B. Wilson,R. Arcilla,C.L. Dunford,Said F. Mughabghab,Boris Pritychenko,D. Rochman,Alejandro Sonzogni,C.R. Lubitz,T.H. Trumbull,J.P. Weinman,David Brown,D.E. Cullen,David P. Heinrichs,D. P. McNabb,Herve Derrien,Michael E Dunn,Nancy M. Larson,Luiz C Leal,Allan D. Carlson,R.C. Block,J.B. Briggs,E.T. Cheng,H.C. Huria,M.L. Zerkle,K.S. Kozier,A. Courcelle,V.G. Pronyaev,S. C. van der Marck +47 more
TL;DR: The ENDF/B-VII.0 as discussed by the authors file contains data primarily for reactions with incident neutrons, protons, and photons on almost 400 isotopes, based on experimental data and theory predictions.
Journal ArticleDOI
Shell effects in nuclear masses and deformation energies
TL;DR: In this paper, the authors calculate the shell-model correction to the liquid drop energy of the nucleus as a function of the occupation number and deformation, and show a strong correlation between the shell correction and nucleon level density at the Fermi energy.
Journal ArticleDOI
The Mechanism of nuclear fission
TL;DR: On the basis of the liquid drop model of atomic nuclei, an account of the mechanism of nuclear fission is given in this article, where conclusions are drawn regarding the variation from nucleus to nucleus of the critical energy required for fission, and regarding the dependence of fission cross section for a given nucleus on energy of the exciting agency.