Dresden 2000 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 11: Physik mit schweren Ionen II / Experiment und Theorie
HK 11.3: Vortrag
Montag, 20. März 2000, 17:15–17:30, B 114
Perspectives for using radioactive beams in production of superheavy nuclei — •G. Adamian1,2, N. Antonenko1,2, and W. Scheid1 — 1Institut für Theoretische Physik der Uni. Gießen — 2Joint Institute for Nuclear Research, Dubna
The dependence of the fusion cross section on the isotopic composition of colliding nuclei is analysed within the dinuclear system concept for compound nucleus formation. The evolution of the dinuclear system to the compound nucleus is described as an increase of the mass asymmetry by nucleon transfer from the light nucleus to the heavy one. Probabilities of fusion and surviving probabilities, ingredients of the evaporation residue cross sections, depend decisively on the neutron numbers of the dinuclear system. For example, the fusion probabilities are decreased when the neutron numbers of the projectile deviate from the magic numbers. Evaporation residue cross sections for the production of actinides and superheavy nuclei with charge numbers Z=104–118 are discussed. The comparison of calculated cross sections in cold fusion reactions with existing experimental data supports the dinuclear system concept. Neutron-rich radioactive projectiles are shown to lead to similar fusion cross sections in Pb-based reactions as stable projectiles. The cross sections for the synthesis of the heaviest elements in nearly symmetric reactions are very high due to small fusion barriers. More asymmetric reactions with radioactive beams could be more useful in the production of superheavies.
Supported by AvH–Stiftung(Bonn) and DFG(Bonn)