Abstract
Fragment mass distributions are presented obtained in the heavy-ion reactions22Ne+249Cf,32S+238U,40Ar+232Th and56Fe+208Pb leading to composite systems with equal nuclear charge numberZ=108. The experiments were performed at the heavy-ion cyclotron U 300 of the Laboratory of Nuclear Reactions in Dubna. The spectrometer DEMAS was used to measure the time-of-flight values and the laboratory angles of the correlated fragments. The shape of the mass distributions strongly depends on the initial mass asymmetry. When decreasing the bombarding energy down to values near the Coulomb barrier, the mass distributions obtained in the reactions32S+238U and40Ar+232Th exhibit relative maxima ofM≈205 interpreted to be due to stabilizing effects of nuclear shells during the fragmentation process.
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Grégoire, C., Ngô, C., Remaud, B.: Phys. Lett.99B, 17 (1981); Nucl. Phys. A383, 392 (1982)
Heusch, B., Volant, C., Freiesleben, H., Chestnut, R.P., Hildenbrand, K.D., Pühlhofer, F., Schneider, W.F.W., Kohlmeyer, B., Pfeffer, W.: Z. Phys. A — Atoms and Nuclei288, 391 (1978)
Lebrun, C., Hanappe, F., Lecolley, J.F., Lefebvres, F., Ngô, C., Péter, J., Tamain, B.: Nucl. Phys. A321, 207 (1979)
Töke, J., Bock, R., Dai, G.X., Gralla, S., Gobbi, A., Hildenbrand, K.D., Kuzminski, J., Müller, W.F.J., Olmi, A., Stelzer, H., Back, B.B., Bjørnholm, S.: Nucl. Phys. A440, 327 (1985)
Bjørnholm, S., Swiatecki, W.J.: Nucl. Phys. A391, 471 (1982)
Swiatecki, W.J.: Nucl. Phys. A428, 199c (1984)
Lützenkirchen, K., Kratz, J.V., Wirth, G., Bruechle, W., Suemmerer, K., Lucas, R., Poitou, J., Grégoire, C.: Preprint GSI-85-52. Nucl. Phys. A452, 351 (1986)
Lojewski, Z., Pashkevich, V.V., Cwiok, S.: Nucl. Phys. A436, 499 (1985)
Schilling, K.D., Gippner, P., Seidel, W., Stary, F., Will, E., Heidel, K., Lukyanov, S.M., Penionzhkevich, Yu.E., Salamatin, V.S., Sodan, H., Chubarian, G.G.: Report ZfK-586 (1986); Nucl. Instrum. Methods (submitted for publication)
Will, E., Sodan, H., Lukyanov, S.M., Nosokin, V.I., Penionzhkevich, Yu.E., Salamatin, V.S., Chubarian, G.G., Gippner, P., Seidel, W., Stary, F., Schilling, K.D.: Report JINR 13-85-754, Dubna 1985 (in russian)
Gippner, P., Seidel, W., Manfraß, P., Stary, F., Schilling, K.D., Will, E., Sodan, H., Lukyanov, S.M., Penionzhkevich, Yu. E., Chubarian, G.G.: Report JINR D7-84-736, Dubna 1984, p. 75 (in russian); Annual report ZfK-530 (1984) p. 115
Gippner, P., Schilling, K.D., Seidel, W., Stary, F., Salamatin, V.S., Sodan, H., Lukyanov, S.M.: Report ZfK-572 (1985)
Fromm, W.D., Enghardt, W., Will, E.: Annual report ZfK-488 (1982) p. 186
Will, E.: (to be published)
Ward, D., Forster, J.S., Andrews, H.R., Mitchell, I.V., Ball, G.C., Davies, W.G., Costa, G.J.: At. Energy of Can. Ltd. Report 5313 (1976)
Sodan, H., Will, E., Lukyanov, S.M., Oganessian, Yu.Ts., Penionzhkevich, Yu.E., Chubarian, G.G., Gippner, P., Seidel, W., Schilling, K.D.: JINR Rapid Communications, N4-84, Dubna 1984, p. 15
Lukyanov, S.M., Oganessian, Yu.Ts., Penionzhkevich, Yu.E., Sodan, H., Will, E., Chubarian, G.G., Gippner, P., Seidel, W., Schilling, K.D.: Proceedings of the International Workshop on Gross Properties of Nuclei and Nuclear Excitations XIII, Hirschegg, Austria, 1985, p. 123; Proceedings of the International Conference on nucleus-nucleus collisions, Visby, Sweden, 1985, Vol. 1, p. 56
Gippner, P., Schilling, K.D., Seidel, W., Stary, F., Will, E., Sodan, H., Lukyanov, S.M., Chubarian, G.G., Salamatin, V.S., Penionzhkevich, Yu.E.: Proceedings of the XVth International Symposium on Nuclear Physics/Nuclear Fission, Gaußig, GDR, 1985 (to be published)
Wilcke, W.W., Birkelund, J.R., Wollersheim, H.J., Hoover, A.D., Huizenga, J.R., Schröder, W.U., Tubbs, L.E.: At. Data Nucl. Data Tables25, 389 (1980)
Schmidt, R., Toneev, V.D.: Nukleonika23, 71 (1978)
Toneev, V.D., Schmidt, R.: Yad. Fiz.27, 1191 (1978) (in russian)
Galin, J., Guerreau, D., Lefort, M., Tarrago, X.: Phys. Rev. C9, 1018 (1974)
Glas, D., Mosel, U.: Nucl. Phys. A237, 429 (1975); Nucl. Phys. A264, 268 (1976)
Blocki, J., Randrap, J., Swiatecki, W.J., Tsang, G.F.: Ann. Phys.105, 427 (1977)
Ngo, C., Tamain, B., Beiner, M., Lombard, R.J., Mas, D., Deubler, H.H.: Nucl. Phys. A252, 237 (1975)
Schmidt, R.: Z. Physik A (in press)
Takahashi, K., von Groote, H., Hilf, E.R.: IKDA 76/26, Institut für Kernphysik, TH Darmstadt
Viola, V.E.: Nucl. Data A1, 391 (1966)
Hulet, E.K., Wild, J.F., Dougan, R.J., Lougheed, R.W., Landrum, J.H., Dougan, A.D., Schädel, M., Hahn, R.L., Baisden, P.A., Henderson, C.M., Dupzyk, R.J., Sümmerer, K., Bethune, G.R.: Phys. Rev. Lett.56, 313 (1986)
Kalpakchieva, R., Kartavenko, V.G., Oganessian, Yu.Ts., Penionzhkevich, Yu.E., Sodan, H.: Nukleonika24, 4, 417 (1979)
Kalpakchieva, R., Oganessian, Yu.Ts., Penionzhkevich, Yu.E., Sodan, H.: Z. Phys. A — Atoms and Nuclei283, 253 (1977)
Bock, R., Chu, Y.T., Dakowski, M., Gobbi, A., Grosse, E., Olmi, A., Sann, H., Schwalm, D., Lynen, U., Müller, W., Bjørnholm, S., Esbensen, H., Wölfli, W., Morenzoni, E.: Nucl. Phys. A388, 334 (1982)
Adeev, G.D., Pashkevich, V.V., Saupe, G.: Report JINR (to be published)
Ledergerber, T., Pauli, H.-C.: Nucl. Phys. A207, 1 (1973)
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The authors wish to express their gratitude to Profs. K.H. Kaun and Yu.Ts. Oganessian for their interest in and support of the work. We are grateful to Drs. W. Enghardt and W.D. Fromm for delivering the conception and first variant of the data acquisition program. The comprehensive and steady technical assistance of J. Fiedler, R. Förster, I. Heidel and K. Heidel is gratefully acknowledged. Finally, we wish to thank the staff of the cyclotron U 300 for providing a broad spectrum of heavy ions.
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Gippner, P., Schilling, K.D., Seidel, W. et al. Shell effects in the evolution of the mass asymmetry in heavy-ion collisions leading to composite systems withZ=108. Z. Physik A - Atomic Nuclei 325, 335–346 (1986). https://doi.org/10.1007/BF01294618
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DOI: https://doi.org/10.1007/BF01294618