scholarly journals Complex fragment emission from low energy compound nucleus decay to multifragmentation

1995 ◽  
Vol 45 (7-8) ◽  
pp. 611-623
Author(s):  
L. G. Moretto ◽  
K. X. Jing ◽  
L. Phair ◽  
K. Tso ◽  
G. J. Wozniak
1969 ◽  
Vol 47 (24) ◽  
pp. 2763-2777 ◽  
Author(s):  
C. T. Tindle ◽  
E. Vogt

A comparison is made between the R-matrix and S-matrix theories of low-energy compound nucleus resonances for the particular case of two-level interference. The (p,γ) and (p,n) cross sections of 14C for proton energies between 0.7 and 1.5 MeV are analyzed using both theories. The 15N compound nucleus in this region exhibits strong two-level interference. The two theories provide equally good fits to the data, but the parameters describing the compound-nucleus levels are quite different. A general analytic method of relating the two sets of parameters is derived and shown to give good agreement with the results obtained by curve-fitting procedures. Remarks are made concerning the general behavior of the parameters under strong interference conditions and also on the inclusion of many channels into the analysis.


1972 ◽  
Vol 50 (20) ◽  
pp. 2385-2390 ◽  
Author(s):  
G. R. Norman ◽  
W. V. Prestwich ◽  
T. J. Kennett

Total neutron cross sections for six elements in the 2S–1D shell have been measured in the energy region 0.8–3.0 MeV using a new method. The experiment utilizes the fast neutron flux from a nuclear reactor with the neutron energies being determined by a measurement of their time of flight.From the present results the resonance parameters for aluminum have been determined and examined in the context of earlier low energy results for this element. The observed widths, which range to greater than 100 keV, are found to be consistent with compound nucleus formation when the reduced widths are compared with the corresponding low energy data. It is concluded that the observation of resonances with large widths is not sufficient to discount compound nucleus formation.


2020 ◽  
Vol 19 ◽  
pp. 151
Author(s):  
M. Kokkoris

The theoretical evaluation of diÆerential cross-section values for low-energy re- actions of light elements is of great importance in the fields of IBA (Ion Beam Analysis) and nuclear astrophysics. R-matrix theory is generally accepted as the most appropriate one for the analysis of resonance reactions in low-energy nuclear physics. In this approach, the configuration space of the scattering problem is divided into an internal region, corresponding to the compound nucleus, where the total wave function can be expanded into a complete set of eigenstates (in terms of unknown base functions, with the energy eigenvalues and the matrix elements of the base functions being adjustable parameters) and an external region, where the possible combinations of coupled particle pairs exist, corresponding to the reaction channels that emerge from the compound nucleus. This division of space is made by the choice of the boundary of the compound nucleus, i.e. an appropriate nuclear radius is chosen for each reaction channel. The R-matrix takes account of all the interactions which occur inside the nucleus. In the present work, results obtained in the specific case of elastic scattering and charged-particle nuclear reactions, namely for the 12C+p system are presented.


2012 ◽  
Vol 85 (6) ◽  
Author(s):  
S. Kundu ◽  
C. Bhattacharya ◽  
K. Banerjee ◽  
T. K. Rana ◽  
S. Bhattacharya ◽  
...  
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