Analysis of Electron-Atom Collisions: Spin-Dependent Effects

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


At low energies, particularly below 100 eV, the principal spin-dependent interaction is exchange between the free electron and the bound atomic electrons. Electron exchange is a quantum phenomenon for which no classical model exists. Exchange occurs regardless of spin direction. Its spin dependence is rooted in the Pauli principle: Two electrons with antiparallel spins are distinguishable (one can tell whether exchange took place), whereas with parallel spins they are indistinguishable (exchange can happen but its occurrence cannot be determined experimentally). In quantum theory distinguishable and indistinguishable processes are treated differently; in the latter case the amplitudes for “direct” and “exchange” scattering can interfere. This makes exchange spin dependent.


Atomic Beam Stokes Parameter Lithium Atom Polarization Asymmetry Polarize Electron Beam 
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  1. 1.
    J. Kessler, “Polarized Electrons”, 2nd ed., Springer, Berlin (1985).Google Scholar
  2. 2.
    D. Hils, W. Jitschin, and H. Kleinpoppen, Production of a Highly Polarized Sodium Atomic Beam, Appl.Phys. 25:39 (1981).ADSCrossRefGoogle Scholar
  3. 3.
    G. Baum, C.D. Caldwell, and W. Schröder, Dual-Frequency Optical Pumping for Spin-Polarizing a Lithium Atomic Beam, Appl.Phys. 21:121 (1980).ADSCrossRefGoogle Scholar
  4. 4.
    H. R. Gray, R. M. Whitley, and C. R. Stroud, Jr., Coherent trapping of atomic populations, Opt.Lett. 3:218 (1978).ADSCrossRefGoogle Scholar
  5. 5.
    W. Schröder and G. Baum, A spin flipper for reversal of polarization in a thermal atomic beam, J.Phys. E 16:52 (1983).ADSGoogle Scholar
  6. 6.
    R. N. Watts and C. E. Wieman, The production of a highly polarized atomic cesium beam, Optics Com. 57:45 (1986).CrossRefGoogle Scholar
  7. 7.
    B. Bederson, Crossed-Beam Electron-Neutral Experiments, in: “Methods of Experimental Physics” Vol. 7A, B. Bederson and W.L. Fite, eds., Academic Press, New York (1968), p. 57;Google Scholar
  8. 7.
    B. Jaduszliwer, Optical State Preparation and Analysis for Spin-Effects Studies in Electron-Cesium Collision, Abstract, XV ICPEAC (Brighton, 1987), p. 811.Google Scholar
  9. 8.
    G. Baum et al., to be published.Google Scholar
  10. 9.
    D. T. Pierce and F. Meier, Photoemission of spin-polarized electrons from GaAs, Phys.Rev. B 13:5484 (1976);ADSGoogle Scholar
  11. 9a.
    D. T. Pierce, R. J. Celotta, G.-C. Wang, W. N. Unertl, A. Galejs, C.E. Kuyatt, and S. Mielczarek, GaAs spin polarized electron source, Rev.Sci.Instrum. 51:478 (1980);ADSCrossRefGoogle Scholar
  12. 9b.
    E. Reichert and K. Zähringer, Electron Spin Polarization in the Photoemission of NEA GaAs1-xPx, Appl.Phys. A 29:191 (1982);ADSGoogle Scholar
  13. 9c.
    J. Kirschner, H.P. Oepen, and H. Ibach, Energy- and Spin-Analysis of Polarized Photoelectrons from NEA GaAsP, Appl.Phys. A 30:177 (1983);ADSGoogle Scholar
  14. 9d.
    F.C. Tang, M.S. Lubell, K. Rubin, and A. Vasilakis, Operating experiences with a GaAs photo-emission electron source, Rev.Sci.Instrum. 57:3004 (1986).ADSCrossRefGoogle Scholar
  15. 10.
    D. T. Pierce, S. M. Girvin, J. Unguris, and R. J. Celotta, Absorbed current electron spin polarization detector, Rev.Sci.Instrum. 52:1437 (1981).ADSCrossRefGoogle Scholar
  16. 11.
    M. Erbudak and G. Ravano, Spin dependent electron absorption in gold, J.Appl.Phys. 52:5032 (1981).ADSCrossRefGoogle Scholar
  17. 12.
    H. C. Siegmann, D. T. Pierce, and R. J. Celotta, Spin-dependent absorption of electrons in a ferromagnetic metal, Phys.Rev.Lett. 46:452 (1981).ADSCrossRefGoogle Scholar
  18. 13.
    H. Boersch, R. Schliepe, and K.E. Schriefl, Polarized electrons by Mott scattering at bulk targets, Nucl.Phys. A 163:625 (1971);ADSGoogle Scholar
  19. 13a.
    J. Unguris, D.T. Pierce, and R. J. Celotta, Low-energy diffuse scattering electron-spin polarization analyzer, Rev.Sci.Instrum. 57:1314 (1986).ADSCrossRefGoogle Scholar
  20. 14.
    T. J. Gay, À simple optical electron Polarimeter, J.Phys. B 16:L553(1983).ADSGoogle Scholar
  21. 15.
    G. D. Fletcher, T. J. Gay, and M. S. Lubell, New insights into Mott-scattering electron polarimetry, Phys.Rev. A 34:911 (1986).ADSGoogle Scholar
  22. 16.
    A. Gellrich, J. Jost, and J. Kessler, Elimination of in-strumental asymmetries in Mott analyzers, Abstract XV ICPEAC (Brighton, 1987), p. 818.Google Scholar
  23. 17.
    N. Sherman, Coulomb Scattering of Relativistic Electrons by Point Nuclei; Phys.Rev. 103:1601 (1956);ADSMATHCrossRefGoogle Scholar
  24. 17a.
    S.-R. Lin, Elastic Electron Scattering by Screened Nuclei, Phys.Rev. 133:A965 (1964);ADSCrossRefGoogle Scholar
  25. 17b.
    G. Holzwarth and H. J. Meister, Elastic Scattering of Relativistic Electrons by Screened Gold Nuclei, Nucl. Phys. 59:56 (1964); A.W. Ross, M. Fink, and H. Hilderbrandt, Complex Scattering Factors for the Diffraction of Electrons by Gases, in: “International tables of x-rays crystallography”, to be published; W. Bühring (Heidelberg), unpublished;CrossRefGoogle Scholar
  26. 17c.
    V.A. Apalin, I. Ye. Kutikov, I.I. Lukashevich, L.A. Mikaelyan, G.V. Smirnov, and P. Ye. Spivak, Asymmetry in Double Mott Electron Scattering for Energies from 45 to 245 keV, Nucl.Phys. 31:657 (1962);CrossRefGoogle Scholar
  27. 17d.
    J. Van Klinken, Double Scattering of Electrons, Nucl.Phys. 75:161 (1966).CrossRefGoogle Scholar
  28. 18.
    G. D. Fletcher, M. J. Alguard, T. J. Gay, V. W. Hughes, P. F. Wainwright, M. S. Lubell, and W. Raith, Experimental study of spin-exchange effects in elastic and ionizing collisons of polarized electrons with polarized hydrogen atoms, Phys.Rev. A 31:2854 (1985).ADSGoogle Scholar
  29. 19.
    W. L. van Wyngaarden and H. R. Walters, Spin asymmetry parameter for electron-hydrogen scattering: I Elastic Scattering, J.Phys. B 19:1817 (1986).ADSGoogle Scholar
  30. 20.
    G. Baum, M. Mpede, W. Raith, and U. Sillmen, Measurement of Spin Dependence in Low-Energy Elastic Scattering of Electrons from Lithium Atoms, Phys.Rev.Lett. 57:1855 (1986).ADSCrossRefGoogle Scholar
  31. 21.
    O. Berger and J. Kessler, Elastic scattering of polarized electrons from mercury and xenon, J.Phys.B 19:3539 (1986)ADSCrossRefGoogle Scholar
  32. 22.
    E. Reichert and H. Deichsel, Spinpolarisation durch Elek-tronen-Resonanzstreuung an Neon, Phys.Lett. 25A:560 (1967).ADSGoogle Scholar
  33. 23.
    J. J. McClelland, M. H. Kelley, and R. J. Celotta, Spin-Orbit and Exchange Effects in Elastic Scattering of Spin-Polarized Electrons from Spin-Polarized Na Atoms, Phys.Rev.Lett. 58:2198 (1987).ADSCrossRefGoogle Scholar
  34. 24.
    P. S. Farago, On the detection of spin-orbit interaction in the elastic scattering of electrons from one-electron atoms, J.Phys. B 7:L28 (1974).ADSGoogle Scholar
  35. 25.
    D. W. Walker, On the asymmetry in single scattering of electrons from one-electron atoms, J.Phys. B 7:L489 (1974).ADSGoogle Scholar
  36. 26.
    D. W. Walker, Conservation of Total Spin in Electron-Atom Collisions, in: “Electron and Photon Interactions with Atoms”, H. Kleinpoppen and M.R.C. McDowell, eds., Plenum, New York (1976), p. 203.Google Scholar
  37. 27.
    V. D. Ob’edkov and M. J. Van der Wiel, Asymmetry and spin polarisation in scattering of electrons by one-electron atoms, J.Phys. B 11:L329 (1978).ADSGoogle Scholar
  38. 28.
    P. G. Burke and J. F. B. Mitchell, Spin-polarization in the elastic scattering of electrons by one-electron atoms, J.Phys. B 7:214 (1974).ADSGoogle Scholar
  39. 29.
    G. Baum, W. Raith, U. Sillmen, and H. Steidl, Measurement of relative singlet and triplet contributions in inelastic collisions of electrons with low-Z atoms, Abstracts XV ICPEAC (Brighton, 1987) p. 153.Google Scholar
  40. 30.
    M. Eller, P. Naß, and E. Reichert, Polarization transfer in the impact excitation of rubidium by polarized electrons, Abstracts XV ICPEAC (Brighton, 1987), p. 157.Google Scholar
  41. 31.
    A. Wolke, K. Bartschat, K. B1um, G. F. Hanne, and J. Kessler, Investigation of Stokes parameters for studying resonances near threshold for 61So-63P1 excitation of mercury by polarized electrons, J.Phys. B 16:639 (1983).ADSGoogle Scholar
  42. 32.
    G. F. Hanne, Spin Effects in Inelastic Electron-Atom Collisions, Physics Reports 95:95 (1983).ADSCrossRefGoogle Scholar
  43. 33.
    K. Bartschat and K. B1um, Theory and Physical Importance of Integrated State Multipoles, J. Phys. A 304:85 (1982);ADSGoogle Scholar
  44. 33.
    K. B1um and H. Kleinpoppen, Spin-dependent phenomena in inelastic electron-atom collisions, Adv. in At.Mol.Phys. 19:187 (1983).CrossRefGoogle Scholar
  45. 34.
    G. F. Hanne, Orientation and Spin Exchange in Electron-Atom Collisions, Comments At.Mol.Phys. 14:163 (1984).Google Scholar
  46. 35.
    I.V. Hertel and W. Stoll, Collision experiments with laser excited atoms in crossed beams, Adv. At.Mol.Phys. 13:113 (1977).CrossRefGoogle Scholar
  47. 36.
    M. H. Kelley, J. J. McClelland, and R. J. Celotta, Super-elastic scattering of spin-polarized electrons from optically pumped sodium, Abstracts, XV ICPEAC (Brighton, 1987), p. 152.Google Scholar
  48. 37.
    I. V. Hertel, M.H. Kelley, and J. J. McClelland, Analysis of Collisional Alignment and Orientation Studied by Scattering of Spin-Polarized Electrons from Laser-Excited Atoms, Z.Phys. D 6:163 (1987).ADSGoogle Scholar
  49. 38.
    R. Peterkop, Consideration of Exchange in Ionization, Proc.Phys.Soc. 77:1220 (1961).ADSCrossRefGoogle Scholar
  50. 39.
    G. Baum, M. Moede, W. Raith, and W. Schröder, Measurement of spin asymmetries in the electron impact ionization of alkali atoms, J.Phys. B 18:531 (1985).ADSGoogle Scholar
  51. 40.
    A. D. Stauffer, The nodal structure of two-electron wave functions on the Wannier ridge, Phys.Lett. 91A:114 (1982);Google Scholar
  52. 40.
    C.H. Greene and A.R.P. Rau, Effects of symmetry on two-electron escape at threshold, J.Phys. B 16:99 (1983).ADSGoogle Scholar
  53. 41.
    A. Temkin, The energy distribution cross section in thres-hold electron-atom impact ionization, J.Phys. B 7:L450 (1974).ADSGoogle Scholar
  54. 42.
    M. H. Kelley, W. T. Rogers, R. J. Celotta, and S.R. Mielczarek, Near-Threshold Measurements of Spin Dependence of Electron-Impact Ionization, Phys.Rev. Lett. 51:2191 (1983).ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1988

Authors and Affiliations

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

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