Thermodynamics of a finite system of classical particles with short- and long-range interactions and nuclear fragmentation

Abstract We describe a finite inhomogeneous three-dimensional system of classical particles that interact through short- and/or long-range interactions by means of a simple analytical spin model. After working out the thermodynamic properties of the system in the framework of the grand canonical ensemble, it is shown that the system experiences a phase transition at fixed average density in the thermodynamic limit. The phase diagram and the caloric curve are constructed and compared with numerical simulations. The implications of our results concerning the caloric curve are discussed in connection with the interpretation of corresponding experimental data.