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Mass Measurements of Neutron Excessive Nuclei by the (11B,8B) Reaction

  • D. K. Scott
  • C. U. Cardinal
  • P. S. Fisher
  • P. Hudson
  • N. Anyas-Weiss
Conference paper

Abstract

In recent years a number of experimental techniques have been developed to establish the existence of light nuclei which are particle stable on the neutron excessive side of the valley of beta-stability (1). Figure 1 shows the present status of observed particle stable nuclei below silicon, together with the boundaries predicted by two theoretical calculations (2, 3), Most of the new nuclei have been produced in the bombardment of heavy targets with high energy protons or heavy ions. In the work of Poskanzer’s group (4,5,6) a uranium target was bombarded with protons of several GeV, and the new isotopes of 11Li, 14,15B and 17C were detected in a telescope of solid state counters. A similar technique has been used by Thomas et al. (7) to demonstrate the stability of 19N, 21O and recently (1) they may have observed 19C. A further eleven new isotopes, 18C, 20, 21N, 22, 23, 24O, 23, 24, 25F and 25, 26Ne were reported by Artukh et al. (8,9,10), formed in the bombardment of Th by 18O. The stability of 11Li and of five neutron rich isotopes of Na has been demonstrated by Klapisch et al. (11) using an on-line mass spectrometric technique. As illustrated in figure 1, none of these methods is able, at the present time, to yield accurate information on nuclear masses, and such information is essential for the development of theoretical predictions on the limits of nuclear stability. For example, the nuclei 11Li and 19C were initially predicted to be unbound by the Garvey-Kelson mass relations (2,12) although these nuclei are now known to be particle stable. Figure 1 shows further that Garvey and Kelson predict the last stable isotope of oxygen to have mass 28, whereas Vinogradov and Nemirovsky predict (3) the limit at mass 24. Similar discrepancies exist for other isotopes. It seems likely that further progress will only be made by making accurate mass measurements of neutron rich nuclei in order to make a systematic comparison with theoretical predictions. In this paper we report on the feasibility of using the three neutron transfer reaction (11B, 8B) as a technique for direct mass measurements, and apply the method to a determination of the mass-excess of the T=5/2 nucleus 29Mg.

Keywords

Mass Measurement Composite Spectrum High Energy Proton Neutron Rich Isotope Uranium Target 
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.

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References

  1. 1.
    KLAPISCH, R., International Conference on the Properties of Nuclei far removed from the region of β-stability (Leysin 1970 ) p. 21Google Scholar
  2. 2.
    GARVEY, G. T. and KELSON, I., Phys. Rev. Lett., 16, 197 (1966);ADSCrossRefGoogle Scholar
  3. GARVEY, G. T. and KELSON,I., ibid. 23, 689 (1966).Google Scholar
  4. 3.
    VINOGRADOV, B. N. and NEMIROVSKY, P. E., Soy. J. of Nuc. Phys., 10, 290 (1970).Google Scholar
  5. 4.
    POSKANZER, A. M., COSPER, S. W., HYDE, E. K. and CERNY, J., Phys. Rev. Lett., 97, 1271 (1966).ADSCrossRefGoogle Scholar
  6. 5.
    POSKANZER, A. M., BUTLER, G. W., HYDE, E. K., CERNY, J., LANDIS, D.A. and GOULDING, F. S., Phys. Lett., 27B, 414 (1968).CrossRefGoogle Scholar
  7. 6.
    POSKANZER, A. M., BUTLER, G.W. and HYDE, E. K., Phys. Rev., C3, 882 (1971).ADSGoogle Scholar
  8. 7.
    THOMAS, T. D., RAISBECK, G. M,, BOERSTLING, P., GARVEY, G. T. and LYNCH, R. P., Phys. Lett., 27B, 504 (1968).CrossRefGoogle Scholar
  9. 8.
    ARTUKH, A.G., GRIDNEV, G. F., MIKHEEV, V. L. and VOLKOV, V.V., Nuc. Phys., A137, 348 (1969).ADSCrossRefGoogle Scholar
  10. 9.
    ARTUKH, A. G., AVDEICHIKOV, V. V., GRIDNEV, G. F., MIKHEEV, V. L., VOLKOV, V. V. and WILC ZYNSKI, J., Phys. Lett., 31B, 129 (1970).CrossRefGoogle Scholar
  11. 10.
    ARTUKH, A. G., AVDEICHIKOV, V. V., CHELNOKOV, L. P., GRIDNEV, G. F., MIKHEEV, V. L., VAKATOV, V. I., VOLKOV, V. V. and WILCZYNSKI, J., Phys. Lett., 32B, 43 (1970).CrossRefGoogle Scholar
  12. 11.
    KLAPISCH, R., THIBAULT-PHILLIPPE, C., DETRAZ, C., CHAUMONT, J., BERNAS, R. and BECK, E., Phys. Rev. Lett., 23, 652 (1969).ADSCrossRefGoogle Scholar
  13. 12.
    GARVEY, G. T., Ann. Rev, of Nuc. Science, 19, 433 (1969).ADSCrossRefGoogle Scholar
  14. 13.
    BUTLER, G. W., CERNY, J., COSPER, S.W. and McGRATH, R. L., Phys. Rev., 166, 1096 (1968).ADSCrossRefGoogle Scholar
  15. 14.
    TRENTELMAN, G. F,, PREEDOM, B. M, and KASHY, E., Phys. Rev., C3, 2205 (1971).ADSCrossRefGoogle Scholar
  16. 15.
    CERNY, J., COSPER, S.W., BUTLER, G. W., PEHL, R. A., GOULDING, F.S., LANDIS, D. A. and DETRAZ, C., Phys. Rev. Lett., 16, 469 (1969).ADSCrossRefGoogle Scholar
  17. 16.
    CERNY, J., MENDELSON, R. A,, WOZNIAK, C. J., ESTERL, J. F. and HARDY, J. C., Phys. Rev. Lett., 22, 612 (1969).ADSCrossRefGoogle Scholar
  18. 17.
    CERNY, J., CARDINAL, C. U., JACKSON, K. P., SCOTT, D. K. and SHOTTER, A.C., Phys. Rev. Lett., 25, 676 (1970).ADSCrossRefGoogle Scholar
  19. 18.
    FISHER, P. S. and SCOTT, D. K., Nuc. Inst. and Meth., 49, 301 (1967).ADSCrossRefGoogle Scholar
  20. 19.
    NORTHCLIFFE, L. C. and SCHILLING, R. F., Nuclear Data, A7, 233 (1970).ADSCrossRefGoogle Scholar
  21. 20.
    ARMSTRONG, D. D., BEERY, J. G., FLYNN, E. R., HALL, W. S., KEATON, P. W. and KELLOG, M. P., Nuc. Inst. and Meth., 70, 69 (1969).ADSCrossRefGoogle Scholar
  22. 21.
    GARVEY, G. T., GERACE, W. J., JAFFE, R. L., TALMI, L and KELSON, I., Rev. Mod. Phys., 41, No. 4, Part II (1969).Google Scholar
  23. 22.
    ENDT, P. M. and VAN DER LEUN, C., Nuc. Phys., A105, 1 (1967)ADSCrossRefGoogle Scholar
  24. 23.
    AJZENBERG-SELOVE, F., Nuc. Phys. A152, 1 (1970)ADSCrossRefGoogle Scholar
  25. 24.
    ARTUKH, A. G., AVEDICHIKOV, V. V., ERÖ, J., GRIDNEV, G. F., MIKHEEV, V. L., VOLKOV, V. V. and WILCZYNSKI, J., Nuc. Phys. A160, 511 (1971).ADSCrossRefGoogle Scholar
  26. 25.
    ARTUKH, A. G., AVDEICHIKOV, V. V., ERÖ, J., GRIDNEV, G. F., MIKHEEV, V. L., VOLKOV, V. V. and WILCZYNSKI, J., Phys. Lett., 33B, 407 (1970).CrossRefGoogle Scholar

Copyright information

© Plenum Publishing Company Ltd 1972

Authors and Affiliations

  • D. K. Scott
    • 1
  • C. U. Cardinal
    • 1
  • P. S. Fisher
    • 1
  • P. Hudson
    • 1
  • N. Anyas-Weiss
    • 1
  1. 1.Nuclear Physics LaboratoryOxfordUK

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