Complex particle emission from decaying regions of high excitation formed inC12induced reactions onAu197atEA=30MeV

Abstract

Energy spectra of complex nuclei ($Z_f=5-10\mathrm{}$) emitted in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$+${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ collisions at $\frac{E}{A}=30\mathrm{}$ MeV were measured at angles significantly larger than the grazing angle. The angular dependence of these energy spectra gives clear evidence for the emission of these complex fragments prior to the attainment of statistical equilibrium of the compound nucleus. The qualitative features of the data are rather well described by assuming that complex fragments are emitted from a localized region of high excitation which is in the process of equilibration with the surrounding cold nuclear matter or, alternatively, that the target nucleus is shattered into several fragments by the incoming projectile.