Fusion probability of symmetric heavy, nuclear systems determined from evaporation-residue cross sections

1985 ◽  
Vol 441 (2) ◽  
pp. 316-343 ◽  
Author(s):  
C.C. Sahm ◽  
H.G. Clerc ◽  
K.-H. Schmidt ◽  
W. Reisdorf ◽  
P. Armbruster ◽  
...  
Keyword(s):  
Cross Sections ◽  
Evaporation Residue ◽  
Nuclear Systems ◽  
Fusion Probability

scholarly journals Fusion probability of massive nuclei in reactions leading to heavy composite nuclear systems

2019 ◽  
Vol 223 ◽  
pp. 01052
Author(s):  
Roman Sagaidak
Keyword(s):  
Statistical Model ◽  
Cross Sections ◽  
High Probability ◽  
Heavy Nuclei ◽  
Fission Barriers ◽  
Nuclear Systems ◽  
Fusion Probability ◽  
Experimental Values ◽  
Evaporation Residues ◽  
Bp Model

Reactions between massive nuclei show a considerable reduction in fusion-evaporation cross-sections at the Coulomb barrier according to the comparison of experimental values with those calculated by barrier passing (BP) and statistical model (SM) approximations. Reduced fusion cross-sections corresponding to fusion probability PCN<1 are accompanied by a high probability of deep-inelastic and quasi-fission processes arising on the way to fusion. At the same time, the excitation functions for evaporation residues (ERs) obtained in very mass-asymmetric projectile-target combinations are well described in the framework of the BP model (assuming PCN=1) and SM approximations. In the framework of SM, the survivability of produced heavy nuclei can be described with the use of adjusted macroscopic fission barriers. Fusion suppression appears in less asymmetric combinations, for which PCN values can be estimated using survivability obtained for very asymmetric ones leading to the same CN. An attempt was made to systemize the PCN data derived from different projectile-target combinations leading to ERs in the range from Pb to the most heavies, which are compared withPCN values obtained in fission experiments.

scholarly journals Evaporation-residue cross sections: role of the entrance channel

2011 ◽  
Vol 17 ◽  
pp. 09004 ◽  
Author(s):  
Neil Rowley ◽  
Nabila Saffdine Grar
Keyword(s):  
Cross Sections ◽  
Evaporation Residue ◽  
Entrance Channel

scholarly journals Study of cluster structures in nuclei through the ratio method

2020 ◽  
Vol 56 (12) ◽  
Author(s):  
Pierre Capel ◽  
Ronald C. Johnson ◽  
Filomena M. Nunes
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Intermediate Energy ◽  
Halo Nuclei ◽  
Ratio Method ◽  
Angular Distributions ◽  
Neutron Halo ◽  
Target Interaction ◽  
Nuclear Systems ◽  
Reaction Channels

AbstractFor one-neutron halo nuclei, the cross sections for elastic scattering and breakup at intermediate energy exhibit similar angular dependences. The Recoil Excitation and Breakup (REB) model of reactions elegantly explains this feature. It also leads to the idea of a new reaction observable to study the structure of loosely-bound nuclear systems: the Ratio. This observable consists of the ratio of angular distributions for different reaction channels, viz. elastic scattering and breakup, which cancels most of the dependence on the reaction mechanism; in particular it is insensitive to the choice of optical potentials that simulate the projectile-target interaction. This new observable is very sensitive to the structure of the projectile. In this article, we review a series of previous papers, which have introduced the Ratio Method and its extension to low beam energies and proton-halo nuclei.

Investigation of the synthesis of the unknown superheavy nuclei 309,312126

2019 ◽  
Vol 28 (07) ◽  
pp. 1950056 ◽  
Author(s):  
T. V. Nhan Hao ◽  
N. N. Duy ◽  
K. Y. Chae ◽  
N. Quang Hung ◽  
N. Nhu Le
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Charge Asymmetry ◽  
Evaporation Residue ◽  
Fission Process ◽  
Dinuclear System ◽  
Mass Asymmetry ◽  
Interacting Systems ◽  
First Time ◽  
Text Element

In this paper, we applied the method developed by Santhosh and Safoora in [Phys. Rev. C  94 (2016) 024623; 95 (2017) 064611] to theoretically investigate the fusion, evaporation-residue (ER) and fission cross-sections of the synthesis of the unknown superheavy [Formula: see text]126 nuclei produced by using the [Formula: see text]Ni + [Formula: see text]Cf and [Formula: see text]Zn + [Formula: see text]Cm combinations. The charge asymmetry, mass asymmetry and fissility of the DiNuclear System (DNS) in the synthesis of the mentioned combinations are also estimated. The calculated results show that the ER cross-sections for the synthesis of the [Formula: see text]126 nuclei are predicted to be much less than 1.0[Formula: see text]fb. In particular, it has been found that there may exist a valley of the ER cross-sections in the synthesis of a superheavy [Formula: see text] element, which produces the [Formula: see text]126 isotope. Subsequently, a model for the mass dependence of the ER cross-section in the synthesis of the [Formula: see text]126 isotopes has been proposed for the first time. On the other hand, the quasi-fission process strongly dominates over the fusion in the two concerned interacting systems. The present results, together with those reported in the previous studies, indicate that the investigated projectile–target combinations are not capable for the synthesis of the [Formula: see text]126 isotopes due to tiny fusion cross-sections (about 2–3[Formula: see text]zb), which go beyond the limitations of available facilities. Further studies are thus recommended to search for alternative interacting systems. In conclusion, this work provides useful information for the synthesis of the gap isotopes [Formula: see text]126, which have not been well studied up to date.

Evaporation residue cross sections and average neutron multiplicities in the 64Ni+92Zr and 12C+144Sm reactions leading to 156Er

1986 ◽  
Vol 181 (1-2) ◽  
pp. 16-20 ◽  
Author(s):  
R.V.F. Janssens ◽  
R. Holzmann ◽  
W. Henning ◽  
T.L. Khoo ◽  
K.T. Lesko ◽  
...  
Keyword(s):  
Cross Sections ◽  
Evaporation Residue ◽  
Neutron Multiplicities ◽  
Average Neutron

MEASURING CAPTURE CROSS SECTIONS FOR HEAVY-ELEMENT PRODUCTION

2004 ◽  
Vol 13 (01) ◽  
pp. 293-300
Author(s):  
NEIL ROWLEY ◽  
NABILA GRAR
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Reaction Path ◽  
Superheavy Element ◽  
Evaporation Residue ◽  
Capture Cross ◽  
Total Capture ◽  
Capture Cross Sections

The creation of the nucleus of a superheavy element follows an extremely complex reaction path starting with the crossing of an external potential barrier (or distribution of barriers). This is followed by the evolution towards an equilibrated compound nucleus, which takes place in competition with pre-compound-nucleus fission (quasi-fission). Once formed the equilibrated compound nucleus must still survive against true fusion to yield a relatively long-lived evaporation residue. Much of this path is poorly understood, though recently, progress has been made on the role of the entrance-channel in quasi-fission. This will be briefly reported and a method proposed to measure the total capture cross section for such systems directly.

COMPARISON OF THE FUSION-FISSION AND QUASIFISSION MECHANISMS IN HEAVY-ION COLLISIONS

2009 ◽  
Vol 18 (04) ◽  
pp. 841-849 ◽  
Author(s):  
AVAZBEK NASIROV ◽  
GIOVANNI FAZIO ◽  
GIORGIO GIARDINA ◽  
GIUSEPPE MANDAGLIO ◽  
MARINA MANGANARO ◽  
...  
Keyword(s):  
Cross Sections ◽  
Theoretical Method ◽  
Heavy Ion ◽  
Evaporation Residue ◽  
System Model ◽  
Complete Fusion ◽  
Dinuclear System ◽  
Ion Collisions ◽  
Partial Fusion ◽  
Evaporation Residues

The decrease of the evaporation residue yields in reactions with massive nuclei is explained by an increase of the competition between quasifission and complete fusion processes and by the decrease of the survival probability of the heated and rotating nuclei against fission along the de-excitation cascade of the compound nucleus. The experimental data on the yields of evaporation residue, fusion-fission and quasifission fragments in the 48 Ca + 154 Sm reaction are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues of the 48 Ca + 154 Sm reaction have been well reproduced and yields of fission fragments were analyzed using the partial fusion and quasifission cross sections calculated in the dinuclear system model. Such a way of calculation is used to find optimal conditions for the synthesis of the new element Z = 120 (A = 302) by studying the excitation functions of evaporation residues of the 54 Cr + 248 Cm , 58 Fe + 244 Pu , and 64 Ni + 238 U reactions. Our estimations show that the 54 Cr + 248 Cm reaction is preferable in comparison with the two others.

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