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

2004 ◽  
Vol 13 (01) ◽  
pp. 107-112 ◽  
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.

THE FISSION BARRIERS OF HEAVY AND EXOTIC NUCLEI

2010 ◽  
Vol 19 (04) ◽  
pp. 514-520 ◽  
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.

scholarly journals FURTHER MICROSCOPIC STUDIES OF THE FISSION BARRIERS OF HEAVY NUCLEI

2012 ◽  
Vol 21 (05) ◽  
pp. 1250051 ◽  
Author(s):  
T. V. NHAN HAO ◽  
J. LE BLOAS ◽  
MENG-HOCK KOH ◽  
L. BONNEAU ◽  
P. QUENTIN
Keyword(s):  
Spontaneous Fission ◽  
The Self ◽  
Fission Barrier ◽  
Heavy Nuclei ◽  
Barrier Heights ◽  
Fission Barriers ◽  
Self Consistent ◽  
Microscopic Studies ◽  
Mean Fields ◽  
Approximate Treatment

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.

scholarly journals MODIFIED BETHE–WEIZSÄCKER MASS FORMULA WITH ISOTONIC SHIFT AND NEW DRIPLINES

2005 ◽  
Vol 20 (21) ◽  
pp. 1605-1618 ◽  
Author(s):  
P. ROY CHOWDHURY ◽  
C. SAMANTA ◽  
D. N. BASU
Keyword(s):  
Mass Formula ◽  
Liquid Drop ◽  
Macroscopic Model ◽  
Liquid Drop Model ◽  
Nuclear Masses

Nuclear masses are calculated using the modified Bethe–Weizsäcker mass formula in which the isotonic shifts have been incorporated. The results are compared with the improved liquid drop model with isotonic shift. Mass excesses predicted by this method compares well with the microscopic–macroscopic model while being much more simple. The neutron and proton drip lines have been predicted using this modified Bethe–Weizsäcker mass formula with isotonic shifts.

scholarly journals MACROSCOPIC-MICROSCOPIC ENERGY OF ROTATING NUCLEI IN THE FUSION-LIKE DEFORMATION VALLEY

2000 ◽  
Vol 09 (01) ◽  
pp. 51-66 ◽  
Author(s):  
RADU A. GHERGHESCU ◽  
GUY ROYER
Keyword(s):  
Shell Model ◽  
Liquid Drop ◽  
Fission Barrier ◽  
Liquid Drop Model ◽  
Potential Barriers ◽  
Angular Momenta ◽  
Microscopic Origin ◽  
Microscopic Energy ◽  
Rotating Nuclei

The energy of rotating nuclei in the fusion-like deformation valley has been determined within a liquid drop model including the proximity energy, the two-center shell model and the Strutinsky method. The potential barriers of the 84 Zr , 132 Ce , 152 Dy and 192 Hg nuclei have been determined. A first minimum having a microscopic origin and lodging the normally deformed states disappears with increasing angular momenta. The microscopic and macroscopic energies contribute to generate a second minimum where superdeformed states may survive. It becomes progressively the lowest one at intermediate spins. At higher angular momenta, the minimum moves towards the foot of the external fission barrier leading to hyperdeformed quasi-molecular states.

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

2006 ◽  
Vol 15 (02) ◽  
pp. 432-436 ◽  
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.

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

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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