Il Nuovo Cimento D

, Volume 11, Issue 4, pp 635–645 | Cite as

Positron spin relaxation in naphthalene

  • A. Bisi
  • G. Consolati
  • F. Quasso
  • L. Zappa
Article

Summary

The remaining spin polarizationP of positrons was measured in naphthalene against longitudinal magnetic-field strength. The measuring method was based on the relative yield of Ps in triplet and singlet state. In a zero fieldP is reduced to 50% of the initial polarization and approaches 100% upon increasing the applied field to larger values. This effect, which in teflon is quite absent, appears to be determined by the specific behaviour of positrons in naphthalene.

PACS 71.60

Positron states 

Riassunto

La polarizzazione residua di spin,P, di positroni assorbiti in naftalene è stata misurata in funzione del campo magnetico longitudinale applicato. Il metodo di misura è fondato sul rendimento di formazione del positronio in stati di tripletto e singoletto. A campo nullo il valore diP è ridotto al 50% di quello iniziale e tende al 100% al crescere del campo. L’effetto osservato, del tutto assente in teflon, è forse interpretabile in termini di uno specifico comportamento di positroni in naftalene.

Резюме

Измерется остаточная спиновая поляризацияP позитронов в нафталине в зависимости от величины продольного магнитного поля. Метод основан на измерении относительного выходаP s в триплетном и синглетном состоянии. При нулевом полеP уменьшается до 50% от начальной поляризации и увеличивается до 100% при увеличении приложенного поля до боляших значений. Этот эффект, который отсутствует в тефлоне, по-видимому, определяется особым поведением позитронов в нафталине.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. (1).
    C. S. Wu andS. A. Moskowski:Beta Decay (Interscience Publ., New York, N.Y., 1966).Google Scholar
  2. (2).
    L. Grodzins:Progress in Nuclear Physics, Vol.7 (Pergamon Press, New York, N.Y., 1959), p. 165.Google Scholar
  3. (3).
    A. Rich:Rev. Mod. Phys.,53, 127 (1981).CrossRefADSGoogle Scholar
  4. (4).
    A. Rich, J. Van House, D. W. Gidley, R. S. Conti andP. W. Zitzewitz:Appl. Phys. A,43, 275 (1987).CrossRefADSGoogle Scholar
  5. (5).
    S. Berko andA. P. Mills:J. Phys. (Paris) Colloq.,32, C1–287 (1971).Google Scholar
  6. (6).
    D. W. Gidley, A. R. Köymen andT. Weston Capehart:Phys. Rev. Lett.,49, 1779 (1982).CrossRefADSGoogle Scholar
  7. (7).
    J. Van House andP. W. Zitzewitz:Phys. Rev. A,29, 96 (1984).CrossRefADSGoogle Scholar
  8. (8).
    A. Seeger, J. Major andF. Banhart:Phys. Status Solidi A,102, 91 (1987).Google Scholar
  9. (9).
    A. Bisi, G. Consolati, G. Gambarini andL. Zappa:Nuovo Cimento D,6, 183 (1985).ADSGoogle Scholar
  10. (10).
    G. Maier, U. Haeberlen andH. C. Wolf:Phys. Lett. A,25, 323 (1967).CrossRefADSGoogle Scholar
  11. (11).
    P. Reineker andH. Haken:Z. Phys.,250, 300 (1972).CrossRefADSGoogle Scholar
  12. (12).
    H. Haken andE. Schwartzer:Chem. Phys. Lett.,27, 41 (1974).CrossRefADSGoogle Scholar
  13. (13).
    E. Schwartzer andH. Haken:Phys. Status Solidi B,84, 253 (1977).Google Scholar
  14. (14).
    W. M. Kenkre andP. Reineker:Exciton Dynamics in Molecular Crystals and Aggregates, Springer Tracts in Modern Physics, Vol.94 (Springer-Verlag, Berlin, 1982). p. 111.Google Scholar
  15. (15).
    O. Halpern:Phys. Rev.,94, 904 (1954).MATHCrossRefADSGoogle Scholar
  16. (16).
    A. P. Mills:J. Chem. Phys.,62, 2646 (1975).CrossRefADSGoogle Scholar
  17. (17).
    A. Bisi, G. Consolati andL. Zappa:Hyperfine Interactions,36, 29 (1987).CrossRefADSGoogle Scholar
  18. (18).
    A. Bisi, G. Gambarini andL. Zappa:Nuovo Cimento B,53, 428 (1979).CrossRefADSGoogle Scholar
  19. (19).
    M. Bertolaccini, A. Bisi, G. Gambarini andL. Zappa:J. Phys. C,7, 3827 (1974).CrossRefADSGoogle Scholar
  20. (20).
    G. Bouchiat andJ. M. Lévy-Leblond:Nuovo Cimento,33, 193 (1964).Google Scholar
  21. (21).
    A. Schenck:Muon Spin Rotation Spectroscopy (Bristol/Boston, 1985), p. 43.Google Scholar
  22. (22).
    W. Brandt: inPositron Solid State Physics, edited byW. Brandt andA. Dupasquier (North-Holland, Amsterdam, 1983), p. 10.Google Scholar
  23. (23).
    R. Kubo andT. Toyabe: inMagnetic Resonance and Relaxation, edited byR. Blinc (North-Holland, amsterdam, 1967), p. 810.Google Scholar
  24. (24).
    R. S. Hayano, Y. J. Uemura, J. Imazato, N. Nishida, T. Yamazaki andR. Kubo:Phys. Rev. B,20, 850 (1979).CrossRefADSGoogle Scholar

Copyright information

© Società Italiana di Fisica 1989

Authors and Affiliations

  • A. Bisi
    • 1
  • G. Consolati
    • 1
  • F. Quasso
    • 1
  • L. Zappa
    • 1
  1. 1.Istituto di Fisica del PolitecnicoMilanoItalia

Personalised recommendations