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).

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

FUSION BY DIFFUSION MODEL REVISITED

2011 ◽  
Vol 20 (02) ◽  
pp. 308-315 ◽  
Author(s):  
T. CAP ◽  
K. SIWEK-WILCZYŃSKA ◽  
J. WILCZYŃSKI
Keyword(s):  
Angular Momentum ◽  
Diffusion Model ◽  
Cold Fusion ◽  
Hindrance Factor ◽  
Superheavy Nuclei ◽  
Momentum Dependence ◽  
Fusion Reactions ◽  
Excitation Functions ◽  
Complete Set

A complete set of 27 excitation functions for synthesis of superheavy nuclei produced in cold fusion reactions was analyzed in terms of the "Fusion by Diffusion Model" of Światecki et al., modified to account for the angular momentum dependence of the fusion hindrance factor. The data on cold fusion reactions originate from experiments carried out at GSI Darmstadt, RIKEN Tokyo and LBNL Berkeley in which 208 Pb and 209 Bi targets were bombarded with the variety of projectiles ranging from 48,50 Ti to 70 Zn .

EXPECTATIONS AND LIMITS TO SYNTHESIZE NUCLEI WITH Z ≥ 120

2010 ◽  
Vol 19 (05n06) ◽  
pp. 882-893 ◽  
Author(s):  
G. GIARDINA ◽  
G. FAZIO ◽  
G. MANDAGLIO ◽  
M. MANGANARO ◽  
A. K. NASIROV ◽  
...  
Keyword(s):  
Cross Section ◽  
Cold Fusion ◽  
Evaporation Residue ◽  
Superheavy Elements ◽  
Asymmetric Reactions ◽  
Radioactive Beam ◽  
Superheavy Nuclei ◽  
Formation Probability ◽  
Fusion Probability ◽  
Evaporation Residue Cross Section

In order to explore the possibilities to synthesize the new superheavy elements with Z =120, 122, 124, 126 some hot-fusion (mass asymmetric) reactions and cold-fusion (less mass asymmetric) reactions are studied. The dynamics of reaction with massive nuclei and the formation probability of heavy and superheavy elements with Z =90-126 in the asymmetric and symmetric reactions are discussed. The systematics of fusion probability P CN and evaporation residue cross section σER in these reactions are presented. Moreover, we explore the possibility of synthesis of superheavy nuclei by the use of reaction with the neutron rich radioactive beam 132 Sn , and by symmetric reactions like 136 Xe +136 Xe and 139,149 La + 139,149 La .

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