Skip to main content
Log in

Excited states in neutron deficient even-even thorium isotopes (218≦A≦222)

  • Published:
Zeitschrift für Physik A Atoms and Nuclei

Abstract

The nuclei218, 220, 222Th were investigated by conversion electron andγ-ray spectroscopy after compound nucleus reactions of14N with209Bi and16, 18O with208Pb. The intenseγ-background from fission was suppressed by spectroscopy of conversion electrons andγ-rays in coincidence with the evaporation residues or theirα-decay. Level schemes were determined for218Th up toI π=10+ and for220Th and222Th up toI π=15. The observed structure of218Th may be explained in the spherical shell model with residual interaction by two neutron excitation. ForN≧130 completely different level schemes are observed showing very intense, collective electric dipole transitions (B(E1)−10−2 W.u.) with energies of typically 200 keV. Interpretation in terms of stable octupole deformations of the ground state as well as in anα-cluster picture are discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Möller, P., Nix, J.R.: Nucl. Phys. A361, 117 (1981)

    Google Scholar 

  2. Chevallier, A., Chevallier, J., Haas, B., Khazrouni, S., Schulz, N.: Z. Phys. A — Atoms and Nuclei308, 277 (1982)

    Google Scholar 

  3. Fernández-Niello, J., Puchta, H., Riess, F., Trautmann, W.: Nucl. Phys. A391, 221 (1982)

    Google Scholar 

  4. Leander, G.A., Sheline, R.K., Möller, P., Olanders, P., Ragnarsson, I., Sierk, A.J.: Nucl. Phys. A388, 452 (1982)

    Google Scholar 

  5. Iachello, F., Jackson, A.D.: Phys. Lett.108 B, 151 (1982)

    Google Scholar 

  6. Alhassid, Y., Gai, M., Bertsch, G.F.: Phys. Rev. Lett.49, 1482 (1982)

    Google Scholar 

  7. Dudek, J., Nazarewicz, W., Szymanski, Z.: Phys. Rev. C26, 1708 (1982)

    Google Scholar 

  8. Gai, M., Ennis, J.F., Ruscev, M., Schloemer, E.C., Shivakumar, B., Sterbenz, S.M., Tsoupas, N., Bromley, D.A.: Phys. Rev. Lett.51, 646 (1983)

    Google Scholar 

  9. Itoh, Y., Gono, Y., Kubo, T., Sugawara, M., Nomura, T.: Nucl. Phys. A410, 156 (1983)

    Google Scholar 

  10. Lönnroth, T., Horn, D., Baktash, C., Lister, C.J., Young, G.R.: Phys. Rev. C27, 180 (1983)

    Google Scholar 

  11. Dukelsky, J., Fernández-Niello, J., Sofia, H.M., Perazzo, R.P.J.: Phys. Rev. C28, 2183 (1983)

    Google Scholar 

  12. Daley, H., Iachello, F.: Phys. Lett.131 B, 281 (1983)

    Google Scholar 

  13. Roy, N., Decman, D.J., Kluge, H., Maier, K.H., Maj, A., Mittag, C., Fernández-Niello, J., Puchta, H., Riess, F.: Nucl. Phys. A426, 379 (1984)

    Google Scholar 

  14. Leander, G.A., Sheline, R.K.: Nucl. Phys. A413, 375 (1984)

    Google Scholar 

  15. Nazarewicz, W., Olanders, P., Ragnarsson, I., Dudek, J., Leander, G.A.: Phys. Rev. Lett.52, 1272 (1984)

    Google Scholar 

  16. Nazarewicz, W., Olanders, P., Ragnarsson, I., Dudek, J., Leander, G.A., Möller, P., Ruchowska, E.: Nucl. Phys. A429, 269 (1984)

    Google Scholar 

  17. Daley, H., Gai, M.: Phys. Lett.149 B, 13 (1984)

    Google Scholar 

  18. Piepenbring, R.: J. Phys. (Paris) Lett.45, 1023 (1984)

    Google Scholar 

  19. Stephens, F.S., Asaro, F., Perlman, I.: Phys. Rev.100, 1543 (1955)

    Google Scholar 

  20. Christy, R.F. quoted by Alder, K., et al.: Rev. Mod. Phys.28, 541 (1956)

    Google Scholar 

  21. Neergård, K., Vogel, P.: Nucl. Phys. A145, 33 (1970); A149, 209, 217 (1970)

    Google Scholar 

  22. Kurcewicz, W., Kaffrell, N., Trautmann. N., Plochocki, A., Zylicz, J., Stryczniewicz, K., Yutlandov, I.: Nucl. Phys. A270, 175 (1976)

    Google Scholar 

  23. Kurcewicz, W., Kaffrell, N., Trautmann, N., Plochocki, A., Zylicz, J., Matul, M., Stryczniewicz, K.: Nucl. Phys. A289, 1 (1977)

    Google Scholar 

  24. Kurcewicz, W., Ruchowska, E., Kaffrell, N., Björnstad, T., Nyman, G.: Nucl. Phys. A356, 15 (1981)

    Google Scholar 

  25. Bohr, A., Mottelson, B.: Nuclear structure. Vol. 2. New York: Benjamin 1975

    Google Scholar 

  26. Vermeulen, D.: Report GSI-84-2 of Gesellschaft für Schwerionenforschung, unpublished (1984)

  27. Schmidt, K.H., Faust, W., Münzenberg, G., Reisdorf, W., Clerc, H.G., Vermeulen, D., Lang, W.: Physics and chemistry of fission 1979. Vol. I, S. 409. Wien: IAEA 1980

    Google Scholar 

  28. Dahlinger, M., Bonin, W., Kankeleit, E., Backe, H.: Nucl. Instrum. Methods219, 513 (1984)

    Google Scholar 

  29. Reisdorf, W.: Annual Scientific Report 1980 of the Gesellschaft für Schwerionenforschung, GSI 81-2, 73. Darmstadt 1981

  30. Meyer, L.: Phys. Status Solidi B44, 253 (1971)

    Google Scholar 

  31. Backe, H., Richter, L., Willwater, R., Kankeleit, E., Kuphal, E., Nakayama, Y., Martin, B.: Z. Phys. A — Atoms and Nuclei285, 159 (1978)

    Google Scholar 

  32. Utsunomiya, H., Nomura, T., Inamura, T., Sugitate, T., Motobayashi, T.: Nucl. Phys. A334, 127 (1980)

    Google Scholar 

  33. Goerlach, U., Habs, D., Metag, V., Schwartz, B., Specht, H.J., Backe, H.: Phys. Rev. Lett.48, 1160 (1982)

    Google Scholar 

  34. Yamazaki, T.: Nucl. Data A3, 1 (1967)

    Google Scholar 

  35. Pelte, D., Schwalm, D.: In: Heavy ion collisions. Bock, R. (ed.), Vol. 3. Amsterdam, New York, Oxford: North Holland 1982

    Google Scholar 

  36. Metag, V., Habs, D., Specht, H.J.: Phys. Rep.65, 1 (1980)

    Google Scholar 

  37. Puchta, H.: Talk presented at the Workshop on Electromagnetic Properties of High Spin States, Rehovot, Israel, January 1984

  38. Grodzins, L.: Phys. Lett.2, 88 (1962)

    Google Scholar 

  39. Bonin, W., Dahlinger, M., Glienke, S., Kankeleit, E., Krämer, M., Habs, D., Schwartz, B., Backe, H.: Z. Phys. A — Atoms and Nuclei310, 249 (1983)

    Google Scholar 

  40. Ward, D., Dracoulis, G.D., Leigh, J.R., Charity, R.J., Hinde, D.J., Newton, J.O.: Nucl. Phys. A406, 591 (1983)

    Google Scholar 

  41. Chevallier, A., Chevallier, J., Khazrouni, S., Kraus, L., Linck, I., Radford, D.C., Schulz, N.: J. Phys. (Paris)43, 1597 (1982)

    Google Scholar 

  42. Table of Isotopes. Lederer, M.C., Shirley, V.S. (eds.) 7th Edn. New York: Wiley 1978; and references therein.

    Google Scholar 

  43. Lönnroth, T.: Research report JYFL RR 4/81 of university of Jyväskylä (Finland), unpublished (1981)

  44. Lederer, C.M.: Phys. Rev. C24, 1175 (1981)

    Google Scholar 

  45. Gai, M.: Private communication (1984)

  46. Bohr, A., Mottelson, B.: Nucl. Phys.4, 529 (1957)

    Google Scholar 

  47. Bohr, A., Mottelson, B.: Nucl. Phys.9, 687 (1958)

    Google Scholar 

  48. Nazarewicz, W., Olanders, P.: Preprint Lund-MPh-84/11 (1984)

  49. Dahlinger, M., Hanelt, E., Kankeleit, E., Schwartz, B., Schwalm, D., Habs, D., Simon, R.S., Backe, H.: Z. Phys. A — Atoms and Nuclei321, 535 (1985)

    Google Scholar 

  50. Nörenberg, W.: In: Heavy ion collisions. Bock, R. (ed.), Vol. 2. Amsterdam, New York, Oxford: North Holland 1980

    Google Scholar 

  51. Rösel, F., Fries, H.M., Alder, K., Pauli, H.C.: At. Data Nucl. Data Tables A21, 91 (1978)

    Google Scholar 

  52. Hardt, K., Schüler, P., Günther, C., Recht, J., Blume, K.P., Wilzek, H.: Nucl. Phys. A419, 34 (1984)

    Google Scholar 

  53. Lauterbach, C., Boer, J. de, Mittag, C., Riess, F., Schandera, C., Briançon, C., Lefebvre, A., Simon, R.S.: Annual Scientific Report 1982 of the Gesellschaft für Schwerionenforschung, GSI 83-1, 57. Darmstadt 1983

Download references

Author information

Authors and Affiliations

Authors

Additional information

Darmstädter Dissertation D17

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bonin, W., Backe, H., Dahlinger, M. et al. Excited states in neutron deficient even-even thorium isotopes (218≦A≦222). Z Physik A 322, 59–73 (1985). https://doi.org/10.1007/BF01412018

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01412018

PACS

Navigation