Statistical nature of cluster emission in nuclear liquid phase

Abstract

The emission of nuclear clusters is investigated within the framework of isospin dependent lattice gas model and classical molecular dynamics model. It is found that the emission of individual cluster which is heavier than proton is almost Poissonian except near the liquid gas phase transition point and the thermal scaling is observed by the linear Arrhenius plots which is made from the average multiplicity of each cluster versus the inverse of temperature in the nuclear liquid phase. It indicates of a statistical nature of such cluster emission in the models. The "emission barriers" which are the slopes of the Arrhenius plots are extracted as a function of the mass or charge number and fitted by the formula embodied with the contributions of the surface energy and Coulomb interaction. The possible influences of the source size, Coulomb interaction and "freeze-out" density and related physical implications are discussed.