scholarly journals Ground State Positronium Formation Cross Sections for Scattering of Positrons from Li

1991 ◽  
Vol 44 (5) ◽  
pp. 515 ◽  
Author(s):  
KK Mukherjee ◽  
N Ranjit Singh ◽  
Keka Basu Choudhury ◽  
PS Mazumdar ◽  
S Brajamani
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Ground State ◽  
Positronium Formation ◽  
Distorted Wave ◽  
Total Cross Sections ◽  
Wave Approximation ◽  
Theoretical Predictions

Total cross sections for positronium formation in e+-Li scattering have been studied in the framework of the distorted wave approximation in the energy range 1-50 eV by taking consistent account of the effect of the target distortion. The results are compared with existing theoretical predictions.

scholarly journals Positronium Formation Cross Sections for Scattering of Positrons from Potassium and Rubidium

1994 ◽  
Vol 47 (3) ◽  
pp. 265
Author(s):  
N Ranjit Singh ◽  
NC Deb ◽  
Th Subodh Chandra Singh ◽  
M Babuyaima Singh ◽  
PS Mazumdar
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Positronium Formation ◽  
Distorted Wave ◽  
Total Cross Sections ◽  
Wave Approximation ◽  
Theoretical Results

Total cross sections for positronium formation in positron-potassium and positron-rubidium scattering have been calculated in a distorted wave approximation for incident positrons in the energy range 1 to 50 eV. The present results are compared with other theoretical results and with measurement where available.

Distorted wave calculation of the positronium formation in positron-sodium and positron-potassium scattering

1998 ◽  
Vol 08 (04) ◽  
pp. 217-224
Author(s):  
K. B. Choudhury ◽  
M. Bhattacharya ◽  
N. C. Deb ◽  
N. R. Singh ◽  
M. B. Singh ◽  
...  
Keyword(s):  
Cross Sections ◽  
Positronium Formation ◽  
Distorted Wave ◽  
Total Cross Sections ◽  
Wave Approximation ◽  
Experimental Findings ◽  
Wave Calculation

Total cross sections for the positronium formation in the ground ( n =1) and excited ( n =2) states in e+ - Na and e+ - K scattering have been studied within the framework of a distorted wave approximation. The present results have been compared with other theoretical and experimental findings.

Gamma-ray yields from the reaction D(p, γ)3He at low energies

1970 ◽  
Vol 48 (24) ◽  
pp. 3059-3061 ◽  
Author(s):  
G. M. Bailey ◽  
G. M. Griffiths ◽  
M. A. Olivo ◽  
R. L. Helmer
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Gamma Ray ◽  
Total Cross Sections ◽  
Isotropic Component ◽  
Low Energies ◽  
Theoretical Predictions ◽  
Γ Ray ◽  
Deuterated Polyethylene

Total cross sections and measurements of the small isotropic component of the γ-ray yield from the reaction D(p, γ)3He have been determined in the energy range from 57 to 1100 KeV using gas and deuterated polyethylene targets. The results are compared with some theoretical predictions.

Measurements of total and (or) positronium-formation cross sections for positrons scattered by alkali, magnesium, and hydrogen atoms

1996 ◽  
Vol 74 (7-8) ◽  
pp. 313-333 ◽  
Author(s):  
T. S. Stein ◽  
J. Jiang ◽  
W. E. Kauppila ◽  
C. K. Kwan ◽  
H. Li ◽  
...  
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Positronium Formation ◽  
Projectile Energy ◽  
Hydrogen Atoms ◽  
Positron Energy ◽  
Total Cross Sections ◽  
Alkali Atoms ◽  
Low Energies

Recent developments in measurements of total and (or) positronium-formation cross sections for positrons (in the range of 1 to 300 eV) scattered by alkali, magnesium, and hydrogen atoms are reviewed. Measurements of total and positronium (Ps)-formation cross sections for positrons scattered by sodium, potassium, and rubidium have revealed an interesting pattern of differences and similarities between these collision systems. These measurements, together with recent calculations, provide evidence that coupling effects between Ps formation and other scattering channels are very important at low energies for the alkali atoms. The calculations also indicate that formation of Ps in excited states in the cases of potassium and rubidium is more likely than formation in the ground state when the positron energy is greater than about 5 eV. Measurements of total and Ps-formation cross sections for positrons scattered by magnesium are in a preliminary stage, but the differences between them and the results of available theoretical calculations are providing a strong incentive to intensify experimental and theoretical investigations of this collision system. Refinements in a recently developed technique for measuring total cross sections for positrons and electrons scattered by atomic hydrogen have led to preliminary new results for these systems that are in very good agreement with recent theoretical calculations. These measurements, together with the calculations with which they agree, indicate that as the projectile energy is increased through the higher energy range (above 50 eV), the total cross sections for positrons approach the corresponding results for electrons from above, which is the reverse of the relationship between the positron and electron total cross sections in this energy range for all of the room-temperature gases that have been investigated, except possibly for molecular hydrogen.

Excitation of the 3D states of helium by electrons and positrons

1996 ◽  
Vol 74 (7-8) ◽  
pp. 509-517 ◽  
Author(s):  
Surbhi Verma ◽  
Rajesh Srivastava
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Ground State ◽  
Stokes Parameters ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Distorted Wave ◽  
Positron Impact ◽  
Wave Approximation ◽  
Electrons And Positrons

Distorted-wave approximation calculations were carried out for the electron-impact excitation of 31,3D states from the 11S ground state of helium. Results are presented at an electron energy of 40 eV for the Stokes parameters P1-P4; coherence parameters Pl, γ, [Formula: see text], ρ00; and differential cross sections where most other theoretical and experimental data are available for comparison. The calculation is further extended to the positron-impact 11S–31D excitation in helium and comparison with the corresponding electron-impact results is discussed.

Electron impact ionization of the ground state of singly ionized helium

2000 ◽  
Vol 78 (10) ◽  
pp. 901-906 ◽  
Author(s):  
M Bhattacharya ◽  
N C Deb ◽  
A Z Msezane ◽  
P S Mazumdar
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Differential Cross ◽  
Ground State ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Experimental Results ◽  
Distorted Wave ◽  
Wave Approximation ◽  
34.50 Fa

We calculate the total and single differential cross sections for the electron impact ionization of the ground state of singly ionized helium at various energies in a distorted wave approximation. Present results are compared with existing theoretical and experimental results. PACS Nos.: 34.80.Dp, 34.50.Fa

scholarly journals Total Ionisation Cross Sections in e??H(2S) Scattering

1989 ◽  
Vol 42 (5) ◽  
pp. 475 ◽  
Author(s):  
KK Mukherjee ◽  
Keka Basu Choudhury ◽  
N Ranjit Singh ◽  
PS Mazumdar ◽  
S Brajamani
Keyword(s):  
Cross Sections ◽  
Atomic Hydrogen ◽  
Wave Method ◽  
Distorted Wave ◽  
Total Cross Sections ◽  
Theoretical Predictions ◽  
Impact Ionisation ◽  
Distorted Wave Method ◽  
Final Channel ◽  
Experimental Findings

Total cross sections for the electron impact ionisation from the 2S state of atomic hydrogen have been calculated in the energy range 5 �1-68 eV of the incident electron by using a rigorous distorted wave method in which the effects of both the initial and final channel distortions are taken into account. The present results show improved agreement with experimental findings in comparison with other theoretical predictions.

Neutron total cross sections in the energy range 80 to 150 MeV

1966 ◽  
Vol 85 (1) ◽  
pp. 129-141 ◽  
Author(s):  
D.F. Measday ◽  
J.N. Palmieri
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Total Cross Sections
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