Fragment isospin distributions and the phase diagram of excited nuclear systems

Abstract

Fragment average isospin distributions are investigated within a microcanonical multifragmentation model in different regions of the phase diagram. The results indicate that in the liquid phase $<N/Z>$ versus $Z$ is monotonically increasing, in the phase coexistence region it has a rise and fall shape and in the gas phase it is constant. Deviations from this behavior may manifest at low fragment multiplicity as a consequence of mass/charge conservation. Characterization of the "free" and "bound" phases function of fragment charge reconfirms the neutron enrichment of the "free" phase with respect to the "bound" one irrespectively the localization of the multifragmentation event in the phase diagram.