Abstract
The isotopic distributions of fragments produced in the spallation of uranium are strongly influenced by the fission of the excited prefragments, highly fissile nuclei. The competition between fission and evaporation around the doubly-magic nucleus Pb is discussed. The light fragments from Fe beam are produced with a strong enhancement of even-even nuclei compared to the odd-odd in the region of nuclei with equal number of neutrons and protons, N ∼ Z. This staggering in the production of light fragments is not observed in the production of heavy fragments, and is in contradiction with the basis of the statistical model of deexcitation of a hot nucleus. Pairing interaction as a function of the excitation energy and as a function of the isospin of the nucleus are questioned.
Original language | English (US) |
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Pages (from-to) | 85-91 |
Number of pages | 7 |
Journal | Acta Physica Hungarica New Series Heavy Ion Physics |
Volume | 16 |
Issue number | 1-4 |
DOIs | |
State | Published - 2002 |
Keywords
- Fission probabilities
- Proton-neutron pairing
- Shell effect in level densities
- Spallation reaction
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy(all)