scholarly journals Positron Impact Ionisation of H and He Atoms: The Continuum Model

1991 ◽  
Vol 44 (3) ◽  
pp. 265 ◽  
Author(s):  
K Ratnavelu
Keyword(s):  
Cross Sections ◽  
Continuum Model ◽  
Optical Potential ◽  
Potential Model ◽  
Experimental Measurements ◽  
Positron Impact ◽  
Optical Potential Model ◽  
Impact Ionisation ◽  
Theoretical Results ◽  
The Continuum

The continuum optical potential model is used to calculate the ionisation cross sections of H and He by positron impact. The present e+-H result is compared with the recent first measurement of e+ -H ionisation cross sections. The e+ -He calculation is also presented, together with the experimental measurements. A comparison with other theoretical results is also given.

RELATIVISTIC OPTICAL MODEL FOR PROTON-NUCLEUS ELASTIC SCATTERING

2002 ◽  
Vol 11 (05) ◽  
pp. 425-436 ◽  
Author(s):  
M. Y. H. FARAG ◽  
M. Y. M. HASSAN
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Optical Potential ◽  
Optical Model ◽  
Potential Model ◽  
Optical Potential Model ◽  
Relativistic Description ◽  
Good Agreement

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.

scholarly journals Positron Scattering from Atoms and Molecules

Atoms ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 29 ◽  
Author(s):  
Sultana N. Nahar ◽  
Bobby Antony
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Cross Sections ◽  
Optical Potential ◽  
Inert Gases ◽  
Positron Impact ◽  
Positron Scattering ◽  
Atoms And Molecules ◽  
Section Data ◽  
Theoretical Approaches

A review on the positron scattering from atoms and molecules is presented in this article. The focus on positron scattering studies is on the rise due to their presence in various fields and application of cross section data in such environments. Positron scattering is usually investigated using theoretical approaches that are similar to those for electron scattering, being its anti-particle. However, most experimental or theoretical studies are limited to the investigation of electron and positron scattering from inert gases, single electron systems and simple or symmetric molecules. Optical potential and polarized orbital approaches are the widely used methods for investigating positron scattering from atoms. Close coupling approach has also been used for scattering from atoms, but for lighter targets with low energy projectiles. The theoretical approaches have been quite successful in predicting cross sections and agree reasonably well with experimental measurements. The comparison is generally good for electrons for both elastic and inelastic scatterings cross sections, while spin polarization has been critical due to its sensitive perturbing interaction. Positron scattering cross sections show relatively less features than that of electron scattering. The features of positron impact elastic scattering have been consistent with experiment, while total cross section requires significant improvement. For scattering from molecules, utilization of both spherical complex optical potential and R-matrix methods have proved to be efficient in predicting cross sections in their respective energy ranges. The results obtained shows reasonable comparison with most of the existing data, wherever available. In the present article we illustrate these findings with a list of comprehensive references to data sources, albeit not exhaustive.

scholarly journals Comparative analysis of proximity potentials to describe scattering of 13C projectile off 12C, 16O, 28Si and 208Pb nuclei

2018 ◽  
Vol 64 (2) ◽  
pp. 149 ◽  
Author(s):  
M. Aygun
Keyword(s):  
Experimental Data ◽  
Comparative Analysis ◽  
Elastic Scattering ◽  
Cross Sections ◽  
Optical Potential ◽  
Saxon Potential ◽  
208Pb Target ◽  
Scattering Cross Sections ◽  
First Time ◽  
Theoretical Results

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.

α-Cluster Optical Potential Model of 40Ca

2017 ◽  
Vol 47 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Zakaria M. M. Mahmoud ◽  
Kassem O. Behairy
Keyword(s):  
Optical Potential ◽  
Potential Model ◽  
Optical Potential Model

scholarly journals Positron Impact Excitation of the nS States of Atomic Hydrogen

Atoms ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 9 ◽  
Author(s):  
Anand K. Bhatia
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Born Approximation ◽  
Atomic Hydrogen ◽  
Impact Excitation ◽  
Orbital Method ◽  
Positron Impact ◽  
Excitation Cross Sections ◽  
Theoretical Results ◽  
Incident Positron

The excitation cross sections of the nS states, n = 2 to 6, of atomic hydrogen at various incident positron energies (10.23 to 300 eV) were calculated using the variational polarized-orbital method. Nine partial waves were used to obtain converged cross sections. The present results should be useful for comparison with results obtained from other theories and approximations. The positron-impact cross section was found to be higher than the electron-impact cross sections. Experimental and other theoretical results are discussed. The threshold law of excitation is discussed and the cross sections in this region were seen to obey the threshold law proportional to ( ln k f ) − 2 . Cross sections were calculated in the Born approximation also and compared to those obtained using the variational polarized orbital method.

Using the microscopic optical potential model to analyze 10,11Be elastic scattering on protons and nuclei

2014 ◽  
Vol 78 (11) ◽  
pp. 1101-1107
Author(s):  
V. K. Lukyanov ◽  
D. N. Kadrev ◽  
E. V. Zemlyanaya ◽  
A. N. Antonov ◽  
K. V. Lukyanov ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Optical Potential ◽  
Potential Model ◽  
Optical Potential Model ◽  
Microscopic Optical Potential
Sign in / Sign up

Export Citation Format

Share Document