Global features of dissipative processes in light heavy-ion collisions

Abstract

The F-19+Al-27 and F-19+C-12 collisions at incident energies of 111.4, 125, 136.9 MeV and 111.4, 136.9 MeV respectively, have been studied. Continuous energy and angular distributions for 5 less than or equal to Z less than or equal to 16 reaction products have been measured. The correlations between different physical observables show similar trends with the case of much heavier interacting systems. Thus, a complete dynamics, from quasielastic to complete dissipation regime, is evidenced also in the reactions between light nuclei, The interaction time, extracted from the experimental angular distributions, increases with increasing total kinetic energy loss from 10(-23) s up to 10(-21) s Based on simple assumptions about the underlying microscopic reaction mechanisms, semiempirical relationships are suggested and applied to account for the systematic features of the element distributions measured in light-, medium- and heavy-nuclei collisions. Absolute cross sections for reaction and nonfusion processes are deduced from the experimental data. Comparison with microscopic dynamical models is presented. (C) 2001 Elsevier Science B.V. All rights reserved.