Formation and decay of hot nuclei in 475 MeV, 2 GeV proton- and 2 GeV3He-induced reactions on Ag, Bi, Au, and U
| Autor: | H. Rossner, B. Gebauer, M. Josset, G. Röschert, B. Lott, D. Guerreau, L. Pienkowski, J. Galin, B. M. Quednau, A. Péghaire, C. Stephan, B. Gatty, D. Jacquet, H. G. Bohlen, Rudolf Siemssen, M. Morjean, S. Leray, H. Fuchs, Joseph Cugnon, U. Jahnke, D. Hilscher, X. Ledoux |
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| Rok vydání: | 1998 |
| Předmět: |
Physics
Nuclear and High Energy Physics Cluster decay Proton 010308 nuclear & particles physics Fission Nuclear Theory 01 natural sciences 7. Clean energy Charged particle Nuclear physics 0103 physical sciences Quasiparticle Particle Neutron Atomic physics Nuclear Experiment 010306 general physics Excitation |
| Zdroj: | Physical Review C. 57:2375-2392 |
| ISSN: | 1089-490X 0556-2813 |
| Popis: | The formation and decay of hot nuclei generated in the interaction of light projectiles (475 MeV and 2 GeV protons and 2 GeV He-3) on a series of targets (Ag-107, Au-197, Bi-209, and U-238) are studied with an apparatus combining the efficient detection of neutrons in 4 pi sr and an accurate characterization of light charged particles, intermediate-mass fragments (IMF's), and fission fragments. A two-step approach with an intranuclear cascade process for modeling the initial off-equilibrium phase of the collision followed by a classical step-by-step evaporation-including fission competition-is used to reproduce the data. It is inferred from the model, which is found to reproduce several data sensitive to heat, that nuclei with temperatures exceeding T =5 MeV are produced for a sizable part of the events, thus giving the opportunity to study the behavior of hot nuclei free from strong collective excitations which generally accompany nucleus-nucleus collisions. Most of the observed features related to particle emission or more specifically to particle evaporation are rather well accounted for by the model calculation. The evaporationlike IMF emission is generally rather weak, and does not show any rapid onset at the highest excitation energies as would have been expected in a genuine thermal multifragmentation process. Binary fission of the U-like target is shown to be a fairly probable channel at most excitation energies. Some of the characteristics of the fission channel are satisfactorily reproduced, but not all. [S0556-2813(98)02605-3]. |
| Databáze: | OpenAIRE |
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