scholarly journals Calculation of Electron Impact Ionisation of Atomic Hydrogen with the Exact Final-state Boundary Conditions

1994 ◽  
Vol 47 (2) ◽  
pp. 123 ◽  
Author(s):  
Dmitry A Konovalov ◽  
Ian E McCarthy
Keyword(s):  
Cross Sections ◽  
Electron Correlation ◽  
Theoretical Method ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Final State ◽  
Exact Boundary ◽  
State Boundary ◽  
Impact Ionisation ◽  
Theory And Experiment

We present a new and very powerful theoretical method-a distorted-wave Born approximation (DWBA) with an arbitrary final-state electron-electron correlation function. This method combines the flexibility of including any theoretically desired electron-electron correlation and the physical clarity of the DWBA method. Calculations explore the use of an auxiliary final-state wave function with the exact boundary condition, in attempting to describe the absolute cross sections for ionisation of helium in coplanar symmetric kinematics and to resolve discrepancies between theory and experiment.

scholarly journals Distorted-wave Born Approximation for the Ionisation of Hydrogen by Electrons

1990 ◽  
Vol 43 (3) ◽  
pp. 291 ◽  
Author(s):  
IE McCarthy ◽  
X Zhang
Keyword(s):  
Boundary Condition ◽  
Cross Sections ◽  
Differential Cross ◽  
Born Approximation ◽  
Matrix Elements ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Atom Scattering ◽  
Exact Boundary ◽  
Important Direction

Matrix elements for ionisation play an important part in electron-atom scattering calculations. Two methods for describing ionisation that can be incorporated into a scattering calculation are tested here against coplanar asymmetric experimental differential cross sections at 150 and 250 eV. They are the distorted-wave Born approximation and the coupled pseudostates method. A method that incorporates the exact boundary condition for three charged bodies describes the data significantly better and shows an important direction for improvement of scattering calculations.

Analysing powers and differential cross sections of (3He,p) reactions on 6Li and 7Li at low energy

1995 ◽  
Vol 73 (1-2) ◽  
pp. 74-84 ◽  
Author(s):  
D. Baddou ◽  
C. Rioux ◽  
R. J. Slobodrian ◽  
J. M. Nelson
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Born Approximation ◽  
Low Energy ◽  
Angular Distributions ◽  
Differential Cross Sections ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Nucleon Transfer ◽  
Cluster Transfer

Angular distributions of the differential cross sections and analysing powers were measured at an energy of 4.6 MeV. The results are compared with the distorted wave Born approximation predictions for two-nucleon transfer and for a deuteron-cluster transfer. The agreement is qualitative at best, and a discussion of alternatives to improve it is presented.

Zero-range distorted-wave Born approximation analysis of (p,t) transfer reactions

1981 ◽  
Vol 59 (2) ◽  
pp. 231-237 ◽  
Author(s):  
J. J. Bevelacqua ◽  
S. V. Prewett
Keyword(s):  
Form Factor ◽  
Cross Sections ◽  
Born Approximation ◽  
Surface Reaction ◽  
Target Surface ◽  
Transfer Reactions ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Zero Range ◽  
Approximation Analysis

Zero-range distorted-wave Born approximation calculations are used to investigate the systematics of two-nucleon transfer reactions. The shapes of the calculated 40Ca(t,p)42Ca(gs) and 208Pb(p,t)206Pb(gs) cross sections are relatively insensitive to details of the core plus two-neutron form factor, if the form factor tails have similar shapes. Studies of heavy targets such as 206Pb suggest a surface reaction mechanism, but lighter targets (16O and 40Ca) indicate that spatial regions beyond the target surface provide the dominant contribution to the (p,t) cross section.

Measurement and analysis of 10B +12C elastic scattering at energy of 41.3MeV

2019 ◽  
Vol 28 (04) ◽  
pp. 1950028 ◽  
Author(s):  
N. Burtebayev ◽  
M. Nassurlla ◽  
A. Sabidolda ◽  
S. B. Sakuta ◽  
A. A. Karakhodjaev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Cross Sections ◽  
Optical Model ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Measurement And Analysis ◽  
Spectroscopic Amplitude ◽  
Deuteron Transfer ◽  
Forward Hemisphere

Angular distribution of the [Formula: see text] elastic scattering was measured at [Formula: see text][Formula: see text]MeV. Experimental data showed a significant increase in differential cross-sections at backward angles. The optical model with phenomenological potentials reproduces well the experimental cross-sections in the region of the angles of the forward hemisphere, but is not able to explain the increase in cross-sections at large angles. The distorted wave Born approximation method was used to reproduce the experimental data at large angles [Formula: see text] by taking into consideration a deuteron transfer. Spectroscopic amplitude has been extracted for the configuration [Formula: see text]C[Formula: see text]B + [Formula: see text] from the analysis.

Superoperator methods of calculating cross sections: II. Distorted wave Born approximation

1976 ◽  
Vol 54 (13) ◽  
pp. 1328-1342 ◽  
Author(s):  
R. F. Snider ◽  
R. E. Turner
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Correlation Functions ◽  
Born Approximation ◽  
Collision Cross Section ◽  
Internal State ◽  
Time Correlation ◽  
State Transitions ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation

The superoperator form of the collision cross section is evaluated within the distorted wave Born approximation. It is first verified that the obvious expansion methods give a result identical to that obtained by standard methods. Formalistically, the algebraic expansions of the transition operator and superoperator are shown to have parallel structures. The distorted wave Born approximation for the cross section also has a structure parallel to the structure of the Born approximation cross section. This is especially brought out by formulating the results in terms of time correlation functions. Certain simplifying features are found for cross sections averaged over initial and final velocity directions. These cross sections for internal state transitions are further simplified by averaging over a Maxwellian distribution of initial velocities in such a way as to obtain 'kinetic cross sections' appropriate for gas kinetic phenomena. Connection is also made with the 'constant acceleration approximation' used to estimate correlation functions in gas phase NMR.

Double differential cross sections in the electron impact ionization of helium

1994 ◽  
Vol 72 (3-4) ◽  
pp. 126-129 ◽  
Author(s):  
S. Brajamani ◽  
N. Ranjit Singh ◽  
M. Babuyaima ◽  
P. S. Mazumdar
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Differential Cross ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Differential Cross Sections ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Wave Approximation ◽  
Final Channel

The double differential cross sections for electron impact ionization of helium are evaluated in the framework of a distorted wave approximation that takes into account the effects of initial channel, final channel, and target distortion. The present results are in fair agreement with the measured values and rigorous DWBA (distorted-wave Born approximation) results of McCarthy and Zhang.

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