Journal of Radioanalytical and Nuclear Chemistry

, Volume 210, Issue 2, pp 309–325 | Cite as

The interaction of slow positrons with organic moecules above and below positronium formation thresholds

  • L. D. HulettJr.
  • Jun Xu
  • S. A. McLuckey
  • D. M. Schrader
Invited Talks


A review is given of the ionization of organic moecules by monoenergetic positrons having energies in the range of 0.5–15 eV. Two mechanisms, unique to positrons, are described. If the kinetic energy of the positron is above the positronium formation threshold, such that electrons can be removed from the molecules to form free positronium atoms, the ionization/fragmentation behavior can be explained qualitatively by a modification of the Ore gap theory. To explain how positrons can ionize and fragment molecules when their kinetic energies are below the positronium formation threshold, it is necessary to assume that energy is transferred to the molecule by the annihilation process. Ionization cross sections for positrons having kinetic energies below the positronium formation threshold are sensitive to molecular size, structure and bond types. Continuing work involves a search for positronium compound formation and measurements of the kinetic energy distributions of ions.


Inorganic Chemistry Kinetic Energy Energy Distribution Molecular Size Ionization 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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    L. D. HULETT Jr, D. L. DONOHUE, JUN XU, T. A. LEWIS, S. A. McLUCKEY, G. L. GLISH, Chem. Phys. Lett., 216 (1993) 236.Google Scholar
  2. 2.
    L. D. HULETT, Jr., D. L. DONOHUE, T. A. LEWIS, Rev. Sci. Instrum., 62 (1991) 2121.Google Scholar
  3. 3.
    S. A. McLUCKEY, G. L. GLISH, D. L. DONOHUE, L. D. HULETT, Jr., Intern. J. Mass. Spect. Ion Proc., 97 (1990) 237.Google Scholar
  4. 4.
    JUN XU, L. D. HULETT, Jr., T. A. LEWIS, D. L. DONOHUE, S. A. McLUCKEY, G. L. GLISH, Physical Rev., A 47 (1993) 1023.Google Scholar
  5. 5.
    C. M. SURKO, A. PASSNER, M. LEVENTHAL, F. J. WYSOCKI, Phys. Rev. Lett., 61 (1988) 1831.PubMedGoogle Scholar
  6. 6.
    The Ore gap model has been reviewed by D. M. SCHRADER and R. E. SVETIC, Can. J. Phys., 60 (1962) 517.Google Scholar
  7. 7.
    P. A. M. DIRAC, Proc. Cambridge Philos. Soc., 26 (1930) 361.Google Scholar
  8. 8.
    H. S. W. MASSEY, Physics Today, 29 (1976) 42.Google Scholar
  9. 9.
    JUN XU, L. D. HULETT, Jr., T. A. LEWIS, D. L. DONOHUE, S. A. McLUCKEY, O. H. CRAWFORD, Phys. Rev., A 49 (1994) R3151.Google Scholar
  10. 10.
    JUN XU, L. D. HULETT, Jr., T. A. LEWIS, S. A. McLUCKEY, Phys. Rev., A, in press.Google Scholar
  11. 11.
    O. H. CRAWFORD, Phys. Rev., A 49 (1994) R3147.Google Scholar
  12. 12.
    D. M. SCHRADER, F. M. JACOBSEN, N.-P. FRANDSEN, U. MIKKELSEN, Phys. Rev. Lett., 69 (1992) 57.PubMedGoogle Scholar
  13. 13.
    D. W. TURNER C. BAKER, A. D. BAKER, C. R. BRUNDLE, Molecular Photoelectron Spectroscopy, Interscience, New York, 1970.Google Scholar
  14. 14.
    S. A. McLUCKEY, unpublished work.Google Scholar

Copyright information

© Akadémiai Kiadó 1996

Authors and Affiliations

  • L. D. HulettJr.
    • 1
  • Jun Xu
    • 1
  • S. A. McLuckey
    • 1
  • D. M. Schrader
    • 2
  1. 1.Chemical and Analytical Sciences DivisionOak Ridge National LaboratoryOak Ridge(USA)
  2. 2.Chemistry DepartmentMarquette UniversityMilwaukee(USA)

Personalised recommendations