ELASTIC SCATTERING OF 28Si–27Al IN A REALISTIC OPTICAL POTENTIAL

1996 ◽  
Vol 05 (03) ◽  
pp. 533-541 ◽  
Author(s):  
M. RASHDAN

Within a realistic model for the optical potential between nuclei based on the solution of the Bethe-Goldstone equation with the Reid soft-core potential, the differential cross-sections of the 28 Si –27 Al system, recently measured at energies around the Coulomb barrier, are calculated. The experimental data are well-reproduced over the entire energy range without any adjustable parameters to fit the cross-section.

2002 ◽  
Vol 11 (05) ◽  
pp. 425-436 ◽  
Author(s):  
M. Y. H. FARAG ◽  
M. Y. M. HASSAN

The relativistic description of the proton-nucleus elastic scattering can be considered within the framework of a relativistic optical potential model. The elastic scattering of proton with the nuclei 12 C , 16 O , 20 Ne , and 24 Mg at 800 MeV and 1.04 GeV are studied for relativistic and nonrelativistic treatments. The real optical potentials and the differential cross sections of these reactions are calculated. The obtained results are compared with the corresponding results obtained from the calculation depending on the Woods–Saxon optical potential which were adjusted to fit the experimental data. The present results are in good agreement with the experimental data.


2014 ◽  
Vol 92 (3) ◽  
pp. 206-215 ◽  
Author(s):  
Mahmudul Hasan ◽  
M. Alfaz Uddin ◽  
M. Ismail Hossain ◽  
A.K.F. Haque ◽  
A.K. Basak

The differential, total, and momentum transfer cross sections along with the minima in the differential cross sections (DCSs) and the Sherman function S(θ) for the elastic scattering of electrons by calcium atoms have been calculated. These calculations are done within the framework of complex electron–atom optical potential and relativistic dynamics, in the energy range 1–2000 eV. The results obtained are in good agreement with the available experimental data and are better than the previous calculations in overall assessment. In the DCSs, the energies and angular positions of five critical minima have been confirmed. In the vicinity of these critical minima, nine maximum polarization points have been found within the range −0.90 ≤ S(θ) ≤ +0.73. Near the critical minima, a strong energy dependence of maximum polarization points is found.


1996 ◽  
Vol 74 (7-8) ◽  
pp. 505-508 ◽  
Author(s):  
R. M. Finch ◽  
Á. Kövér ◽  
M. Charlton ◽  
G. Laricchia

Differential cross sections for elastic scattering and ionization in positron–argon collisions as a function of energy (40–150 eV) are reported at 60°. Of particular interest is the energy range 55–60 eV, where earlier measurements by the Detroit group found a drop in the elastic-scattering cross section of a factor of 2. This structure has been tentatively attributed to a cross channel-coupling effect with an open inelastic-scattering channel, most likely ionization. Our results indicate that ionization remains an important channel over the same energy range and only begins to decrease at an energy above 60 eV.


2018 ◽  
Vol 64 (5) ◽  
pp. 498
Author(s):  
Hocine Aouchiche

Differential and integral cross sections for elastic scattering of electron by NH3 molecule are investigated for the energy ranging from 10 eV to 20 keV.  The calculations are carried out in the framework of partial wave formalism describing the target molecule by means of one center molecular Hartree-Fock functions.  A spherical complex optical potential used includes a static part – obtained here numerically from quantum calculation – and fine effects like correlation, polarization and exchange potentials. The results obtained in this model point out clearly the role played by the exchange and the correlation-polarization contributions in particular at lower scattering angles and lower incident energies. Both differential and integral cross sections obtained are compared with a large set of experimental data available in the literature and well agreement is found throughout the scattering angles and whole energy range investigated here.


The technique of beam superposition is employed in the experimental study of ionization of He+, N+ and 0+ by electrons. The electron energy range extends up to 300 eV. The primary and product ions are mass selected. Relative cross-sections for ionization are obtained as a function of the laboratory energy of the electrons. The experimental data for He+ and N+ are quite consistent with published values of the absolute cross-sections for these systems. By using Thomson’s classical scaling rule for isoelectronic systems, the cross-sections for ionization of O+ are calculated from those for ionization of atomic nitrogen. These values, when normalized to the relative ionization efficiency curve obtained experimentally here, show close overlap over the entire energy range.


1995 ◽  
Vol 10 (38) ◽  
pp. 2915-2921 ◽  
Author(s):  
V.P. MIKHAILYUK

The differential cross-sections for elastic scattering of deuterons on 12 C and 16 O nuclei at 700 MeV are calculated on the basis of multiple diffraction scattering theory and the α-cluster model with dispersion. For d−12 C scattering it was shown that the results of the calculations by the model, when the effects related with the deuteron structure included via deuteron-α amplitude are in better agreement with the experimental data than those by the model, in which incident deuteron is considered as composed of neutron and proton.


1973 ◽  
Vol 51 (20) ◽  
pp. 2197-2201 ◽  
Author(s):  
P. W. Martin ◽  
R. McFadden ◽  
B. L. White

The differential cross sections for 4.3 MeV neutrons elastically scattered from natural samples of U, Bi, and Pb have been measured at laboratory angles of 5, 10, and 15°. In the case of uranium, the data are consistent with calculations based on the nuclear optical model and known electromagnetic interactions. Less satisfactory agreement to the data is obtained in the cross section measurements for lead and bismuth.


2018 ◽  
Vol 64 (2) ◽  
pp. 149 ◽  
Author(s):  
M. Aygun

In this work, we examine the elastic scattering cross sections of 13C on 12C, 16O, 28Si and 208Pb target nuclei at different incident energies. For the first time, we apply six types of proximity potentials such as Broglia andWinther 1991 (BW 91), AageWinther (AW95), Christensen and Winther 1976 (CW 76), Bass 1973 (Bass 73), Bass 1977 (Bass 77) and Bass 1980 (Bass 80) in order to obtain the real part of the optical potential. The imaginary part is taken as the Woods-Saxon potential. Theoretical results are compared with each other as well as the experimental data.


2012 ◽  
Vol 20 ◽  
pp. 89
Author(s):  
V. Paneta ◽  
A. Lagoyannis ◽  
A. Kafkarkou ◽  
M. Kokkoris

Differential cross sections of the 7Li(p,p0)7Li, 7Li(p,p1)7Li, 7Li(p,α0)4He, 19F(p,p0), 19F(p,α0)16O and 19F(p,α1,2)16O reactions have been determined for proton energies Elab=1500-7000 keV, using a variable energy step and for detection angles between 140-170 degrees in steps of 10 degrees. To validate the obtained results, benchmarking measurements were performed, using thick and mirror-polished BaF2 and LiF targets. The experimental data are compared to data from literature, when available, and similarities and discrepancies are presented and analyzed.


1974 ◽  
Vol 29 (8) ◽  
pp. 1143-1151 ◽  
Author(s):  
H.-P. Weise ◽  
H.-U. Mittmann

In the elastic differential cross-section of the N+-rare gas systems two different types of oscillations have been observed. At an energy of a few eV a primary rainbow was detected for all systems. In the case of N+ - Ar, secondary rainbows were resolved too. From these experimental data the potential depths were determined to be: ε (N+ - Ne) = 0.4 eV, ε (N+ - Kr) = 0.29 eV, ε(N+ - Xe) = 0.92 eV. For the system N+ - Ar the shape of the reduced potential was obtained by evaluating the positions of the secondary rainbow extrema. The potential depth was found to be 2.16 eV. At higher energies and large scattering angles additional oscillations appeared which are presumed to be Stueckelberg oscillations. For N+ - Ne a single group of strongly marked oscillations appeared up to the highest energies used (EL = 220 eV). In the case of N+ - Ar the amplitudes of these undulations are strongly quenched. For N+ - Kr and N+ - Xe several groups of oscillations with different amplitudes and frequencies seem to be superimposed in the differential cross-section. They are attributed for all systems to crossings of the incoming state with the charge exchanged state.


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