Abstract
The fission probability of highly excited targetlike nuclei produced in reactions of 2.5 GeV protons on Au, Bi, and U was studied as a function of excitation energy whereby is deduced eventwise from the multiplicity of evaporated light particles. At the highest of 1000 MeV amounts to with all 3 target nuclei irrespective of the initial fissility. Statistical-model calculations satisfactorily reproduce the observed evolution of with —provided that no extra transient delay is introduced. Fission thus is decided upon very fast and early in the long deexcitation chain towards scission which comprises as much as of all evaporated alpha particles.
- Received 3 May 2005
DOI:https://doi.org/10.1103/PhysRevLett.95.162701
©2005 American Physical Society