| B.Fernandez-Dominguez, P.Armbruster, L. Audouin, J.Benlliure, M.Bernas ,A.Boudard, E.Casarejos, S. Czajkowski, J.E.Ducret, T.Enqvist, B.Jurado, R.Legrain, S.Leray, B.Mustapha, J.Pereira, M.Pravikoff, F.Rejmund, M.V.Ricciardi, K.-H.Schmidt,C.Stephan,J.Taieb,L.Tassan-Got,
C.Volant,W.Wlazlo
|
The isotopic distributions and recoil velocities of the fission fragments
produced in the spallation reaction $^{208}Pb+p$ at 500 $A$ MeV have been measured
using the inverse-kinematics technique, a lead beam onto a liquid-hydrogen target,
and the high-resolution spectrometer FRS at GSI. The shapes of the different distributions are found in good agreement
with previously published data while the deduced total fission cross-section is higher than expected from existing systematics. From the experimental
data, the characteristics of the average fissioning system can be reconstructed in charge, mass and
excitation energy, and the number of post-fission neutrons can be inferred. The results are also compared to different models
describing the spallation reaction. The intranuclear cascade code INCL4 followed
by the de-excitation code ABLA is shown to describe reasonably well the evolution
of the isotopic distribution shapes between 500 and 1000 $A$ MeV. |
