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Title: Pairing-induced speedup of nuclear spontaneous fission

Abstract

Collective inertia is strongly influenced at the level crossing at which the quantum system changes its microscopic configuration diabatically. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of these configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of 264Fm and 240Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM* and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of 264Fm, where the effect of triaxiality on the fission barrier is large, the geometry of the fission pathway in the space of the shape degrees of freedom is weakly impacted by pairing. This is not the case formore » 240Pu, where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. As a result, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.« less

Authors:
 [1];  [2];  [3];  [4];  [5]
  1. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Variable Energy Cyclotron Centre, Kolkata (India)
  2. Univ. of Warsaw, Warsaw (Poland); Univ. of Jyvaskyla, Jyvaskyla (Finland); Joint Institute of Nuclear Physics and Applications, Oak Ridge, TN (United States)
  3. Michigan State Univ., East Lansing, MI (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Warsaw, Warsaw (Poland)
  4. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Univ. of M. Curie-Sktodowska, Lublin (Poland)
Publication Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Michigan State Univ., East Lansing, MI (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP); USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1233540
Alternate Identifier(s):
OSTI ID: 1180803
Grant/Contract Number:  
NA0002574; FG02-96ER40963; SC0008499; FG52-09NA29461
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review C, Nuclear Physics
Additional Journal Information:
Journal Volume: 90; Journal Issue: 6; Journal ID: ISSN 0556-2813
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Sadhukhan, Jhilam, Dobaczewski, J., Nazarewicz, W., Sheikh, J. A., and Baran, A. Pairing-induced speedup of nuclear spontaneous fission. United States: N. p., 2014. Web. doi:10.1103/PhysRevC.90.061304.
Sadhukhan, Jhilam, Dobaczewski, J., Nazarewicz, W., Sheikh, J. A., & Baran, A. Pairing-induced speedup of nuclear spontaneous fission. United States. https://doi.org/10.1103/PhysRevC.90.061304
Sadhukhan, Jhilam, Dobaczewski, J., Nazarewicz, W., Sheikh, J. A., and Baran, A. 2014. "Pairing-induced speedup of nuclear spontaneous fission". United States. https://doi.org/10.1103/PhysRevC.90.061304. https://www.osti.gov/servlets/purl/1233540.
@article{osti_1233540,
title = {Pairing-induced speedup of nuclear spontaneous fission},
author = {Sadhukhan, Jhilam and Dobaczewski, J. and Nazarewicz, W. and Sheikh, J. A. and Baran, A.},
abstractNote = {Collective inertia is strongly influenced at the level crossing at which the quantum system changes its microscopic configuration diabatically. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of these configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of 264Fm and 240Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM* and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of 264Fm, where the effect of triaxiality on the fission barrier is large, the geometry of the fission pathway in the space of the shape degrees of freedom is weakly impacted by pairing. This is not the case for 240Pu, where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. As a result, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.},
doi = {10.1103/PhysRevC.90.061304},
url = {https://www.osti.gov/biblio/1233540}, journal = {Physical Review C, Nuclear Physics},
issn = {0556-2813},
number = 6,
volume = 90,
place = {United States},
year = {Mon Dec 22 00:00:00 EST 2014},
month = {Mon Dec 22 00:00:00 EST 2014}
}

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Cited by: 69 works
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Works referenced in this record:

Fission and fusion dynamics
journal, September 1972


Nuclear Constitution and the Interpretation of Fission Phenomena
journal, March 1953


Approaches to nuclear friction
journal, July 1978


Funny Hills: The Shell-Correction Approach to Nuclear Shell Effects and Its Applications to the Fission Process
journal, April 1972


Dynamics and non-adiabaticity in the fission process
journal, November 1975


Excitation during collective deformation: How simple it is
journal, September 1978


Collective motion at large amplitudes and finite velocities
journal, March 1977


Diabatic and adiabatic collective motion in a model pairing system
journal, March 1998


Large superfluidity enhancement in the penetration of the fission barrier
journal, April 1974


On the spontaneous fission of nuclei
journal, January 1966


On the dynamics of fission: The role of reflection asymmetry in the nuclear shape
journal, June 1973


Pairing as a Collective mode
journal, February 2007


Coupling of the pairing vibrations with the fission mode
journal, October 1985


Influence of the pairing vibrations on spontaneous fission probability
journal, November 1989


Cranking mass parameters for fission
journal, March 2010


Spontaneous fission lifetimes from the minimization of self-consistent collective action
journal, December 2013


Breaking of Axial and Reflection Symmetries in Spontaneous Fission of Fermium Isotopes
journal, February 2011


Systematic study of fission barriers of excited superheavy nuclei
journal, July 2009


Microscopic theory of fission dynamics
journal, October 1989


A dynamic analysis of spontaneous-fission half-lives
journal, May 1981


Some dynamical aspects of the fission process
journal, May 1978


Global properties of even-even superheavy nuclei in macroscopic-microscopic models
journal, October 2005


On the impact of large amplitude pairing fluctuations on nuclear spectra
journal, October 2011


Large-amplitude pairing fluctuations in atomic nuclei
journal, December 2013


Hartree-Fock-Bogolyubov description of nuclei near the neutron-drip line
journal, June 1984


Closed shells at drip-line nuclei
journal, January 1995


Quadrupole collective inertia in nuclear fission: Cranking approximation
journal, November 2011


Microscopic description of complex nuclear decay: Multimodal fission
journal, July 2009


Solution of the Skyrme–Hartree–Fock–Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis.
journal, January 2012


Towards a better parametrisation of Skyrme-like effective forces: A critical study of the SkM force
journal, September 1982


Nuclear ground-state properties from mean-field calculations
journal, September 2002


Collective Inertia and Fission Barriers Within the Skyrme-Hartree-Fock Theory
journal, February 2007


Spontaneous fission modes and lifetimes of superheavy elements in the nuclear density functional theory
journal, February 2013


Dynamic versus static fission paths with realistic interactions
journal, November 2014


Nuclear energy density optimization: Large deformations
journal, February 2012


Works referencing / citing this record:

Microscopic theory of nuclear fission: a review
journal, October 2016


Review of metastable states in heavy nuclei
journal, May 2016


The role of shell evolution in shape coexistence
journal, January 2016


r -process nucleosynthesis: connecting rare-isotope beam facilities with the cosmos
journal, July 2019


Review on the progress in nuclear fission—experimental methods and theoretical descriptions
journal, September 2018


Fission properties of superheavy nuclei for r-process calculations
text, January 2017