Abstract
Evaporation residues from the fusion of the nearly symmetric systems86Kr+123Sb and124Sn+94Zr have been detected. The compound nucleus218Th could be produced with an excitation energy as low as 21 MeV. The barriers for the formation of a compound nucleus were deduced from the evaporation residue cross sections. There is no evidence for an additional amount of energy needed to fuse these systems, if compared with the extrapolation of fusion barrier systematics or with results of fusion model calculations not including friction phenomena. One of the systems reaches a value ofZ 1·Z 2=2,000, about the highest value where evaporation residues have ever been observed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bass, R.: Nucl. Phys. A231, 45 (1974)
Blocki, J., Randrup, J., Swiatecki, W.J., Tsang, C.F.: Ann. Phys. (N.Y.)105, 427 (1977)
Wong, C.Y.: Phys. Lett.42B, 186 (1972)
Wilczynski, J.: Nucl. Phys. A216, 386 (1973)
Krappe, H.J.: Nucl. Phys. A269, 493 (1976)
Ngô, H., Ngô, Ch.: Nucl. Phys. A348, 140 (1980)
Møller, P., Nix, J.R.: Nucl. Phys. A272, 502 (1976)
Gross, D.H.E., Kalinowski, H., De, J.N.: Lecture Notes in Physics. Vol. 33, p. 194. Berlin, Heidelberg, New York: Springer 1975
Swiatecki, W.J.: preprint LBL-10911, Lawrence Berkeley Laboratory, Berkeley (1980)
Vaz, L.C., Alexander, J.M., Satchler, G.R.: preprint (1980)
Schmidt, K.-H., Faust, W., Münzenberg, G., Reisdorf, W., Clerc, H.-G., Vermeulen, D., Lang, W.: Proceedings of the International Symposium on Physics and Chemistry of Fission. Jülich 1979. IAEA, Vienna, 1980, Vol. I, p. 409
Münzenberg, G., Faust, W., Hofmann, W., Armbruster, P., Güttner, K., Ewald, H.: Nucl. Instrum. Methods161, 65 (1979)
Schmidt, K.-H., Faust, W., Münzenberg, G., Clerc, H.-G., Lang, W., Pielenz, K., Vermeulen, D., Wohlfahrt, H., Ewald, H., Güttner, K.: Nucl. Phys. A318, 253 (1979)
Vermeulen, D., Clerc, H.-G., Schmidt, K.-H.: In: annual report GSI 79-11, 1979, p. 11
Cohen, S., Plasil, F., Swiatecki, W.J.: Ann. Phys. (N.Y.)82, 557 (1974)
Dahlinger, M., Vermeulen, D., Schmidt, K.-H.: (to be published)
Stokstad, R.G., Reisdorf, W., Hildenbrand, K.D., Kratz, J.V., Wirth, G., Lucas, R., Poitou, J.: Z. Phys. A — Atoms and Nuclei295, 269 (1980)
Esbensen, H.: Nucl. Phys. A352, 147 (1981)
Huizenga, J.R.: ERDA Progress Report C00-3496-56 (1976)
Bondorf, J.P., Sabel, H.I., Sperber, D.: Phys. Rep.15C, 83 (1974)
Krappe, H.J., Nix, J.R., Sierk, A.J.: Phys. Rev.C20, 992 (1979)
Bass, R.: Proceedings of the Symposium on Deep-Inelastic and Fusion Reactions with Heavy Ions, Berlin 1979, p. 281. Berlin, Heidelberg, New York: Springer 1980
Oganessian, Yu.: Lecture Notes in Physics. Vol.33, p. 221. Berlin, Heidelberg, New York: Springer 1975
Bock, R., Chu, Y.T., Gobbi, A., Olmi, A., Sann, H., Lynen, U., Müller, W., Bjørnholm, S., Esbensen, H.: (to be published)
Sikkeland, T., Gäggeler, H.: In: GSI-Annual Report (1980) and (to be published)
Møller, P., Nix, J.R.: preprint LA-UR-80-1996, Los Alamos Scientific Laboratory, Los Alamos (1980)
Ignatyuk, A.V., Itkis, M.G., Okolovich, Smirenkin, G.N., Tishin, A.S.: Sov. I. Nucl. Phys.21, 612 (1975)
Author information
Authors and Affiliations
Additional information
The experiment would not have been possible without the efforts of the UNILAC crew and the assistance of the target laboratory.
This work was supported by BMFT.
Rights and permissions
About this article
Cite this article
Schmidt, K.H., Armbruster, P., Heßberger, F.P. et al. The barrier for compound-nucleus formation in the nearly symmetric systems86Kr+123Sb→209Fr and124Sn +94Zr→218Th. Z Physik A 301, 21–28 (1981). https://doi.org/10.1007/BF01412459
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01412459