A MODIFIED THOMAS-FERMI TREATMENT OF NUCLEI

An improved nuclear Thomas-Fermi theory is studied in which, rather than adding density-gradient corrections to the standard expression for the kinetic energy density (proportional to rho-5/3, where rho is the density) one simply modifies this rho-5/3 function to reflect the fact that the kinetic energy density, becomes negative for small values of rho when, in a typical nuclear problem, one is dealing with the outer fringes of the surface region. The net result of this study is simply stated: in order to find the density associated with a given nuclear potential, one exponentiates this potential instead of raising its depth with respect to the chemical potential to the three-halves power, as in the standard treatment. An improved description of the nuclear surface profile is obtained, including the quantal halo in the classically forbidden region. But since density derivatives are not involved, there is no need to solve a partial differential equation in order to find the density.