Advertisement

Analysis of Electron-Atom Scattering: Positron-Atom Scattering, a Variation of Electron-Atom Scattering

  • Wilhelm Raith
Part of the NATO ASI Series book series (NSSB, volume 181)

Abstract

The interaction of an electron with a (screened) nucleus is attractive, of a positron, repulsive. Classically, hyperbolic trajectories result for the Coulomb scattering of electrons and positrons, but the nucleus is located in the near (inside) focal point for electrons, in the far (outside) one for positrons. Despite this difference the Rutherford cross section is identical for electrons and positrons as only the square of the charge enters into the formula. Similarly, the scattering in First Born Approximation (FBA), without accounting for exchange in the electron case, is identical. Since we consider here only the low-energy scattering below, say, several keV, we can disregard relativistic effects. In this energy range the FBA is the appropriate “high-energy” approximation. In fact, the experimentally determined convergence of electron and positron scattering cross sections can be taken as a criterion for the validity of the FBA.

Keywords

Elastic Scattering Positron Beam Positron Scattering Positron Impact Electron Cross Section 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    “Proceedings of the International Conference on Positron Scattering and Annihilation in Gases”, Can.J.Phys. 60:461 (1982).Google Scholar
  2. 2.
    “Positron Scattering in Gases”, J.W. Humberston and M. R. C. McDowell, eds., Plenum Press, New York, 1984.Google Scholar
  3. 3.
    “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986.Google Scholar
  4. 4.
    “Atomic Physics with Positrons”, J. W. Humberston, ed., Plenum Press, New York, 1988 (in print).Google Scholar
  5. 5.
    G. Sinapius, G. Spicher and H. L. Ravn, Positron sources for atomic physics experiments, J.Phys.E 19:987 (1986).ADSCrossRefGoogle Scholar
  6. 6.
    A. P. Mills, Jr., Brightness Enhancement of Slow Positron Beams, Appl.Phys. 23:189 (1980).ADSCrossRefGoogle Scholar
  7. 7.
    A. P. Mills, Jr. and E.M. Gullikson, Solid Neon Moderator for Poducing Slow Positrons, Appl.Phys.Lett. 49:1121 (1986).ADSCrossRefGoogle Scholar
  8. 8.
    A. Rich, P. W. Zitzewitz, J. Van House, and D. W. Gidley, Spin Polarized Low Energy Positron Beams and Their Applications, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986, p. 190.Google Scholar
  9. 9.
    W. E. Kauppila and T. S. Stein, Positron-gas cross-section measurements, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986, p. 471.Google Scholar
  10. 10.
    G. M. A. Hyder, M. S. Dababneh, Y.-F. Hsieh, W. E. Kauppila, C. K. Kwan, M. Mahdavi-Hezaveh, and T. S. Stein, Positron Differential Elastic-Scattering Cross Section Measurements for Argon, Phys.Rev.Lett. 57:2252 (1986);ADSCrossRefGoogle Scholar
  11. 10a.
    S. J. Smith et al., Low Energy Positron-Argon Differential Elastic Scattering Cross Section Measurements, Abstracts XV ICPEÀC (Brighton 1987), p. 404.Google Scholar
  12. 11.
    S. N. Nahar and J. M. Wadehra, Elastic scattering of posi-trons and electrons from argon, Phys.Rev.A 35:2051 (1987).ADSCrossRefGoogle Scholar
  13. 12.
    R. P. McEachran and A. D. Stauffer, Differential Cross-Sections for Positron Noble Gas Collisons, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986, p. 122.Google Scholar
  14. 13.
    A. Schwab, P. Höner, W. Raith and G. Sinapius, Elastic Differential Positron Scattering from Argon, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986.Google Scholar
  15. 14.
    S. P. Khare, A. Kumar, and K. Lata, Elastic Scattering of Positrons & Electrons by Argon Atoms, Indian J. Pure and App. Phys. 20:379 (1982);Google Scholar
  16. 14a.
    C. J. Joachain and R. M. Potvliege, Differential Cross Sections for Elastic Positron-Argon Scattering, Abstracts, XV ICPEAC (Brighton, 1987), p. 406.Google Scholar
  17. 15.
    D. Fromme, Ionisation von Helium durch Positronen, Disser-tation, Bielefeld 1987.Google Scholar
  18. 16.
    D. P. Dewangan and H. R. Walters, The elastic scattering of electrons and positrons by helium and neon: the distorted-wave second Born approximation, J.Phys.B 10:637 (1977).ADSCrossRefGoogle Scholar
  19. 17.
    A. D. Stauffer and R. P. McEachran, Spin Dependent Effects in the Elastic Scattering of Electrons and Positrons from Heavy Atoms, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986, p. 166.Google Scholar
  20. 18.
    K. Hasenburg, Spin polarization in elastic positron-atom scattering, J.Phys.B 19:L499 (1986).ADSCrossRefGoogle Scholar
  21. 19.
    P. G. Coleman and J. T. Hutton, Excitation of Helium Atoms by Positron Impact, Phys.Rev.Lett. 45:2017 (1980).ADSCrossRefGoogle Scholar
  22. 20.
    R. P. McEachran, L. A. Parcell, A. D. Stauffer, and T. Zuo, Excitation of Helium by Positron Impact and a Comparison with Electron Data, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986.Google Scholar
  23. 21.
    D. Fromme, G. Kruse, W. Raith, and G. Sinapius, Partial-Cross-Section Measurements for Ionization of Helium by Positron Impact, Phys.Rev.Lett. 57:3031 (1986).ADSCrossRefGoogle Scholar
  24. 22.
    H. Klar, Threshold ionisation of atoms by positrons, J.Phys.B 14:4165 (1981).ADSCrossRefGoogle Scholar
  25. 23.
    D. Fromme, G. Kruse, W. Raith, and G. Sinapius, to be published in J.Phys.B.Google Scholar
  26. 24.
    M. Brauner and J. S. Briggs, Ionisation to the projectile continuum by positron and electron collisions with neutral atoms, J.Phys.B 19:L325 (1986).ADSCrossRefGoogle Scholar
  27. 25.
    M. Charlton, G. Laricchia, N. Zafar, and F. M. Jacobsen, Inelastic Positron Collisions in Gases, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986..Google Scholar
  28. 26.
    G. Laricchia, M. Charlton, T. C. Griffith, and G. Clark, Excited State Positronium Formation in Low Density Gases, Phys.Lett. 109A:97 (1985).ADSGoogle Scholar
  29. 27.
    G. Laricchia, M. Charlton, S. A. Davies, C. D. Beling, and T. C. Griffith, The production of collimated beams of o-Ps atoms using charge exchange in positron-gas collisions, J.Phys.B 20:L99 (1987).ADSCrossRefGoogle Scholar
  30. 28.
    K. G. Lynn, A. P. Mills, Jr., L. O. Roellig, and M. Weber, Description of the Intense, Low Energy, Monoenergetic Positron Beam at Brookhaven, in: Electronic and Atomic Collisions, D. C. Lorents, W. E. Meyerhof, and J. R. Peterson, eds., North-Holland, Amsterdam, 1986, p. 227.Google Scholar
  31. 29.
    G. Laricchia, S. A. Davies, M. Charlton, T. C. Griffith, and C. D. Beling, On the production of a timed positronium beam by positron gas scattering, Abstracts, XV ICPEAC (Brighton, 1987), p. 414.Google Scholar
  32. 30.
    F. M. Jacobsen, L. H. Andersen, B. I. Deutch, P. Hvelplund, H. Knudsen, M. Charlton, G. Laricchia, and M. Holzscheiter, On Antihydrogen Production, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986..Google Scholar
  33. 31.
    N. C. Deb, J. McGuire, and N.C. Sil, Electron Capture by Positron in He, Abstract, XV ICPEAC (Brighton, 1987), p. 402.Google Scholar
  34. 32.
    R. I. Campeanu, D. Fromme, G. Kruse, R. P. McEachran, L. A. Parcell, W. Raith, G. Sinapius, and A. D. Stauffer, Partitioning of the positron-helium total scattering cross section, J.Phys.B 20:3557 (1987).ADSCrossRefGoogle Scholar
  35. 33.
    T. S. Stein, M. S. Dababneh, W. E. Kauppila, C. K. Kwan, and Y. J. Wan, Positron-(and Electron-) Alkali Atom Total Scattering Measurements, in: “Positron(Electron)-Gas Scattering”, W. E. Kauppila, T. S. Stein, and J. M. Wadehra, eds., World Scientific, Singapore, 1986..Google Scholar
  36. 34.
    W. E. Kauppila, T. S. Stein, J. H. Smart, M. S. Dababneh, Y. K. Ho, J. P. Downing, and V. Pol, Measurements of total scattering cross sections for intermediate energy positrons and electrons colliding with helium, neon, and argon, Phys.Rev.A 24:725 (1981).ADSCrossRefGoogle Scholar
  37. 35.
    M. S. Dababneh, Y.-F. Hsieh, W. E. Kauppila, V. Pol, and T. S. Stein, Total-scattering cross-section measurements for intermediate-energy positrons and electrons colliding with Kr and Xe, Phys.Rev.A 26:1252 (1982).ADSCrossRefGoogle Scholar
  38. 36.
    P. G. Coleman and J. D. McNutt, Measurement of Differential Cross Sections for the Elastic Scattering of Positrons by Argon Atoms, Phys.Rev.Lett. 42:1130 (1979).ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1988

Authors and Affiliations

  • Wilhelm Raith
    • 1
  1. 1.Fakultät für PhysikUniversität BielefeldBielefeldFed.Rep. of Germany

Personalised recommendations