FURTHER MICROSCOPIC STUDIES OF THE FISSION BARRIERS OF HEAVY NUCLEI

Two systematic sources of error in most current microscopic evaluations of fission-barrier heights are studied. They are concerned with an approximate treatment of the Coulomb exchange terms (known as the Slater approximation) in the self-consistent mean-fields and the projection on good parity states (e.g., of positive parity for the spontaneous fission of an even–even nucleus) of left–right reflection asymmetric intrinsic solutions (e.g., around the second barrier). Approximate or unprojected solutions are shown to lead each to an underestimation of the barrier heights by a few hundred keV.

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THE FISSION BARRIERS OF HEAVY AND EXOTIC NUCLEI

International Journal of Modern Physics E ◽

10.1142/s0218301310014923 ◽

2010 ◽

Vol 19 (04) ◽

pp. 514-520 ◽

Cited By ~ 3

Author(s):

FEDIR IVANYUK ◽

KRZYSZTOF POMORSKI

Keyword(s):

Liquid Drop ◽

Optimal Shape ◽

Exotic Nuclei ◽

Fission Barrier ◽

Heavy Nuclei ◽

Accurate Approximation ◽

Barrier Heights ◽

A Value ◽

Fission Barriers ◽

Experimental Values

We have calculated the liquid drop fission barriers of medium and heavy nuclei within the Lublin-Strasbourg-Drop model. Exploiting in addition the topographical theorem by Myers and Światecki we propose a simple but quite accurate approximation of the fission barrier heights. When comparing the r.m.s. deviation of approximated versus experimental values of fission barrier heights for known nuclei with Z > 70 a value 1.1 MeV is obtained which is comparable with the experimental uncertainties. The Strutinsky optimal shape method is generalized to the left-right asymmetric shapes of nuclei in order to investigate the influence of this degree of freedom on the barrier heights.

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Direct measurement of fission barrier height of unstable heavy nuclei at ISOL facilities

HNPS Proceedings ◽

10.12681/hnps.1922 ◽

2019 ◽

Vol 26 ◽

pp. 51

Author(s):

M. Veselský ◽

J. Klimo ◽

R. Raabe ◽

A. N. Andreyev ◽

M. Huyse ◽

...

Keyword(s):

Barrier Height ◽

Experimental Studies ◽

Fission Barrier ◽

Heavy Nuclei ◽

Radioactive Beams ◽

Active Target ◽

Barrier Heights ◽

Fission Barriers ◽

New Generation ◽

Stability Line

Fission barrier height is one of the least known nuclear parameters, with experimental data, acquired decades ago, existing only close to beta-stability line. Availability of heavy radioactive beams offers possibility to investigate fission of more exotic nuclei and using the state of the art detection technique such as the active target we can even probe their fission barriers heights with precision has not been reached so far. The present status of fission barrier measurement is going to be explained in this paper. We are going to discuss the possibilities to stage experimental studies of fission barrier heights at new generation of ISOL facilities such as HIE-ISOLDE and active target ACTAR TPC. As an example we select the experiment IS581, being prepared for execution at the HIE-ISOLDE facility (CERN).

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COLLECTIVE INERTIA AND FISSION BARRIERS WITHIN THE SKYRME-HARTREE-FOCK THEORY

International Journal of Modern Physics E ◽

10.1142/s0218301307005879 ◽

2007 ◽

Vol 16 (02) ◽

pp. 443-451 ◽

Cited By ~ 14

Author(s):

A. BARAN ◽

A. STASZCZAK ◽

J. DOBACZEWSKI ◽

W. NAZAREWICZ

Keyword(s):

Spontaneous Fission ◽

Correlation Energy ◽

Zero Point ◽

The Self ◽

Bcs Theory ◽

Generator Coordinate Method ◽

Hartree Fock ◽

Generator Coordinate ◽

Fission Barriers ◽

Self Consistent

Spontaneous fission barriers, quadrupole inertia tensor, and zero-point quadrupole correlation energy are calculated for 252,256,258 Fm in the framework of the self-consistent Skyrme-Hartree-Fock+BCS theory. Two ways of computing collective inertia are employed: the Gaussian Overlap Approximation to the Generator Coordinate Method and cranking ansatz. The Skyrme results are compared with those of the Gogny-Hartree-Fock-Bogolyubov model.

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FISSION BARRIERS WITHIN THE LIQUID DROP MODEL WITH THE SURFACE-CURVATURE TERM

International Journal of Modern Physics E ◽

10.1142/s0218301304001801 ◽

2004 ◽

Vol 13 (01) ◽

pp. 107-112 ◽

Cited By ~ 21

Author(s):

K. POMORSKI ◽

J. DUDEK

Keyword(s):

Liquid Drop ◽

Surface Curvature ◽

Fission Barrier ◽

Macroscopic Model ◽

Liquid Drop Model ◽

Barrier Heights ◽

Curvature Term ◽

Fission Barriers ◽

The Masses ◽

Weak Influence

The recently revised liquid drop model (PRC 67(2003) 044316) containing the curvature term reproduces the masses of 2766 experimentally known isotopes having Z≥8 and N≥8 with the r.m.s. deviation equal to 0.698 MeV when the microscopic corrections of Moeller et al. is used. The influence of the congruence energy as well as the compression term on the barrier heights is discussed within this new macroscopic model. The r.m.s. deviation of the fission barrier heights of 40 isotopes with Z≥34 is 1.73 MeV only when deformation-dependent congruence energy is included. The effect of the compression term in the liquid drop energy has rather weak influence on the barrier heights.

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Systematics of Spontaneous-Fission Barrier Heights

Acta Physica Hungarica ◽

10.1556/aph.18.2003.2-4.42 ◽

2003 ◽

Vol 18 (2-4) ◽

pp. 361-362

Author(s):

Z. Patyk ◽

I. Muntian ◽

A. Sobiczewski

Keyword(s):

Spontaneous Fission ◽

Fission Barrier ◽

Barrier Heights

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IMPORTANCE OF MASS ASYMMETRY AND NONAXIALITY FOR THE DESCRIPTION OF FISSION BARRIERS

International Journal of Modern Physics E ◽

10.1142/s0218301306004314 ◽

2006 ◽

Vol 15 (02) ◽

pp. 432-436 ◽

Cited By ~ 2

Author(s):

ARTUR DOBROWOLSKI ◽

KRZYSZTOF POMORSKI ◽

JOHANN BARTEL

Keyword(s):

Substantial Effect ◽

Fission Barrier ◽

Microscopic Model ◽

Mass Asymmetry ◽

Barrier Heights ◽

Fission Barriers

In the framework of the macroscopic-microscopic model fission barriers in the region of actinide nuclei are investigated. Taking left-right mass asymmetric and non-axial shapes into account is demonstrated to have a substantial effect on fission barrier heights.

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ESTIMATION OF THE INACCURACY OF CALCULATED MASSES AND FISSION-BARRIER HEIGHTS OF HEAVY NUCLEI

International Journal of Modern Physics E ◽

10.1142/s0218301311017685 ◽

2011 ◽

Vol 20 (02) ◽

pp. 325-332 ◽

Cited By ~ 4

Author(s):

A. SOBICZEWSKI ◽

P. ROZMEJ

Keyword(s):

Heavy Nucleus ◽

Ground State ◽

Interaction Strength ◽

Fission Barrier ◽

Heavy Nuclei ◽

Pairing Interaction ◽

Microscopic Approach ◽

Barrier Heights ◽

Pairing Strength ◽

Microscopic Models

The inaccuracy of calculated masses M and (static) fission-barrier height [Formula: see text] of heaviest nuclei is estimated. The estimation is performed within a macroscopic-microscopic approach for two nuclei: a heavy nucleus 250 Cf and a superheavy one 294118. The source of the inaccuracy is the inaccuracy of calculated deformation of a nucleus and of calculated pairing-interaction strength. It is shown that the inaccuracy of the ground-state mass M, due to the inaccuracy of the calculated deformation is small, up to about 20 keV. The inaccuracy of M, due to the inaccuracy of the pairing strength is much larger, up to 310 keV. The inaccuracy of [Formula: see text], due to the inaccuracy of the deformation is up to about 70 keV, while this due to the inaccuracy of the pairing strength is up to 520 keV. For both studied nuclei, the calculated inaccuracy of [Formula: see text] is smaller than the discrepancy between the values of [Formula: see text] obtained recently within different macroscopic-microscopic models.

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