Entrance Channel Dependence of Production Cross Sections of Superheavy Nuclei in Cold Fusion Reactions

2005 ◽  
Vol 22 (4) ◽  
pp. 846-849 ◽  
Author(s):  
Feng Zhao-Qing ◽  
Jin Gen-Ming ◽  
Fu Fen ◽  
Zhang Feng-Shou ◽  
Jia Fei ◽  
...  
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Cold Fusion ◽  
Entrance Channel ◽  
Superheavy Nuclei ◽  
Fusion Reactions

CROSS SECTIONS CALCULATED FOR COLD FUSION REACTIONS WITH EMISSION OF ONLY ONE NEUTRON FOR PRODUCING THE HEAVIEST ELEMENTS

2005 ◽  
Vol 14 (03) ◽  
pp. 373-375 ◽  
Author(s):  
ROBERT SMOLAŃCZUK
Keyword(s):  
Cross Sections ◽  
Level Density ◽  
Cold Fusion ◽  
Entrance Channel ◽  
Fusion Reactions ◽  
Coupled Channels ◽  
Dynamical Deformation ◽  
Channel Effects ◽  
The Difference ◽  
Heaviest Elements

Entrance-channel effects in cold fusion reactions that lead to heavy and superheavy nuclei are discussed in the framework of the coupled-channels theory. Dynamical deformation besides collective excitations is taken into account in the entrance channel. Exit channel is described by using the modified statistical model that takes into account the difference between the level density in the equilibrium configuration and that in the saddle-point configuration. Comparison of the calculated fusion cross sections with experimental data is given.

ENTRANCE CHANNEL EFFECT AND FUSION CROSS SECTIONS IN THE SYNTHESIS OF HEAVY AND SUPERHEAVY NUCLEI

2010 ◽  
Vol 19 (08n09) ◽  
pp. 1603-1615
Author(s):  
SAI-SAI DU ◽  
FENG-SHOU ZHANG
Keyword(s):  
Cross Sections ◽  
Nuclear Reactions ◽  
Large Mass ◽  
Entrance Channel ◽  
Superheavy Nuclei ◽  
Fusion Reactions ◽  
Combined System ◽  
Mass Asymmetry ◽  
Channel Effect ◽  
Heavy And Superheavy Nuclei

The entrance channel effect, mainly involved the mass asymmetry, the neutron-excess and the collision orientation of the combined system, are presented by summarizing the recent theoretical results about the fusion reactions leading to the same compound nuclei and the neutron-rich fusion reactions in the synthesis of heavy and superheavy nuclei through various models. It is concluded that the system with large mass asymmetry and neutron-rich nuclear reactions is favorable for the compound nucleus formation.

Influence of entrance channel on production cross sections of superheavy nuclei

2017 ◽  
Vol 96 (2) ◽  
Author(s):  
Xiao Jun Bao ◽  
Shu Qing Guo ◽  
Hong Fei Zhang ◽  
Jun Qing Li
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Entrance Channel ◽  
Superheavy Nuclei

COLD FUSION REACTIONS USING NEUTRON-RICH PROJECTILES

2013 ◽  
Vol 22 (08) ◽  
pp. 1350061 ◽  
Author(s):  
A. SULAKSONO
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Estimation Method ◽  
Cold Fusion ◽  
Evaporation Residue ◽  
Fusion Reactions ◽  
Fusion Barrier ◽  
The Cross ◽  
Evaporation Residues

This paper studies the formation cross-sections of super heavy (SH) nuclei in some cold fusion reactions of radioactive neutron-rich projectiles with double-magic 208 Pb target. In this study, the cross-sections of capture, fusion and evaporation residues in one- and two-neutron (1n and 2n) channels are calculated by using neutron-rich Fe , Ni and Zn projectiles are compared to the cross-sections calculated using stable Fe , Ni and Zn projectiles. The heights of fusion barrier and their positions in all reactions considered in this study are also compared to the heights and positions calculated using the estimation method proposed by Dutt and Puri. For cold fusion reactions with stable Fe , Ni and Zn projectiles, the heights of fusion barrier and the cross-sections of evaporation residues in 1n and 2n channels are compared to their corresponding experimental data. In general, for reactions using projectiles with the same proton number, the neutron-rich projectile is found to yield relatively-heavier mass of SH nucleus and larger evaporation residue cross-section, compared to those of the corresponding stable projectiles. However, in certain reactions, the cross-sections of neutron-rich projectile can be slightly larger or slightly smaller than that of the corresponding stable projectile. This behavior is highly affected by the charge of projectile and the fission barrier of the formed compound nucleus (CN). In addition, the 292114 is found to be the heaviest compound nucleus formed in cold fusion reaction by using neutron-rich nuclei as the projectile, but the cross-section of evaporation residue in one-neutron channel is still around few pico barns (pb).

DYNAMICAL HINDRANCE OF FUSION OF SUPERHEAVY NUCLEI

2006 ◽  
Vol 15 (02) ◽  
pp. 426-431 ◽  
Author(s):  
J. BŁOCKI ◽  
L. SHVEDOV ◽  
J. WILCZYŃSKI
Keyword(s):  
Saddle Point ◽  
White Noise ◽  
Coulomb Barrier ◽  
Cold Fusion ◽  
Langevin Equations ◽  
Superheavy Nuclei ◽  
Multidimensional Space ◽  
Fusion Reactions ◽  
Dissipative Forces ◽  
Fusion Probability

The dynamical hindrance of fusion after the system of two colliding nuclei overcomes the Coulomb barrier is calculated. Langevin equations, in which the stochastic white noise is added to the conservative and dissipative forces, are solved in the multidimensional space. It is shown that in case of very heavy systems the dynamical trajectories lead from the Coulomb barrier towards the fission valley at locations rather outside the saddle point and then turn downward to scission. Only due to fluctuations a small fraction of trajectories can overcome the saddle point and lead to fusion. Fusion probabilities determined by the ratio of fusion-to-scission fluxes are calculated. In cold fusion reactions induced by different projectiles on 208 Pb and 209 Bi targets, the fusion probability drops down by almost ten orders of magnitude for a range of projectiles from 48 Ca (Zcn = 102) to 86 Kr (Zcn = 118).

CALCULATIONS OF CROSS SECTIONS FOR THE SYNTHESIS OF SUPER-HEAVY NUCLEI IN COLD FUSION REACTIONS

2004 ◽  
Vol 13 (01) ◽  
pp. 261-267 ◽  
Author(s):  
W. J. ŚWIATECKI ◽  
K. SIWEK-WILCZYŃSKA ◽  
J. WILCZYŃSKI
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Free Parameter ◽  
Cold Fusion ◽  
One Dimension ◽  
Brownian Diffusion ◽  
Heavy Nuclei ◽  
Fusion Reactions ◽  
Super Heavy Nuclei

The fusion cross sections are considered to be given by the product of three factors: the cross section to overcome the Coulomb barrier, the probability for the resulting system to reach the compound nucleus configuration by diffusion, and the probability for the compound nucleus to survive fission. The first and third factors are treated by more or less conventional equations, and the second by Brownian diffusion in one dimension. Adjusting one free parameter in the theory one can reproduce the twelve measured cross sections to within a factor of two.

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