Scaling Laws, Transient Times and Shell Effects in Helium Induced Nuclear Fission

Abstract

Fission excitation functions of compound nuclei in a mass region where shell effects are expected to be very strong are shown to scale exactly according to the transition state prediction once these shell effects are accounted for. The fact that no deviations from the transition state method have been observed within the experimentally investigated exci-tation energy regime allows one to assign an upper limit for the transient time of 10 −20 seconds. PACS number(s): 25.85.Ge, 24.75.+i

Fusion enhancement with neutron-rich radioactive beams

“…The compound nucleus is 213 Ac, formed at excitation energies of 47-174 MeV. According to PACE [7] simulations with a value of a f /a n = 1.00 [10] and temperature dependent values of a [11], the fraction of the reactions that leads to fission is 0.99 and it does not change appreciably with projectile energy. Furthermore, in our related study of the 38 S + 181 Ta reaction, a measured upper limit of less than 3% for the fraction of reactions leading to residue formation was found.…”