Coulomb instability of hot nuclei

An equation of state for asymmetric nuclear matter is derived and used to investigate the instability of hot nuclei caused by the Coulomb force. This equation of state takes into consideration the effect of degeneracy of the Fermi system. The nucleus is treated as a liquid drop with a sharp edge and a surface tension. Both the liquid and the surrounding vapor are described by the derived equation of state. The equations describing the coexistence between the drop and the vapor are determined and solved. The instability of these hot liquid drops at temperatures above a certain limiting value is verified by the absence of any real solution of the coexistence equations at such temperatures. The value of the limiting temperature depends on the nucleus but is always less than the critical temperature of nuclear matter. It is found that high-order degeneracy effects as well as symmetry energy corrections must be included in the calculation if meaningful information about the bulk and surface properties of hot nuclear matter is to be extracted from any measurements of the limiting temperature.