Charge distributions in low-energy nuclear fission and their relevance to fission dynamics
1981; Elsevier BV; Volume: 361; Issue: 1 Linguagem: Inglês
10.1016/0375-9474(81)90477-2
ISSN1873-1554
AutoresG. Mariolopoulos, Ch. Hamelin, J. Blachot, J.P. Bocquet, R. Brissot, J. Crançon, H. Nifenecker, C. Ristori,
Tópico(s)Nuclear physics research studies
ResumoRadiochemical and energy loss techniques have been used to measure fragment charge distributions in the systems 229Th(nth, f), 235U(n3 MeV, f) and 252Cf(s, f). Together with those previously obtained [233, 235U(nth, f) and 239, 241Pu(nth, f] the results show that these charge distributions depend very sensitively on both the fissioning species and the initial excitation energy. Very strong even-odd effects are present, for example in the charge distribution of 229Th(nth, f) while they almost disappear in 235U(n3 MeV, f). In the 229Th(nth f) and 252Cf(s, f) cases, kinetic energy distributions of the fragments have been obtained. Fragments with even charges are more energetic, on average, than fragments with odd charges. The results are discussed in terms of a rather small probability for pair breaking during the transition from saddle-point to scission. The relationship between even-odd effects in charge distributions and fine structures in mass distributions is also investigated.
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