ENERGY-LEVELS AND LIFETIMES FOR THE 2P(5)3SNL CORE-EXCITED STATES IN NA

Systematic calculations of energies and decay rates for the 2p(5)3snl core-excited states (with n less-than-or-equal-to 7) in Na have been p erformed using a configuration interaction method, including spin orbi t interaction and core-polarization correlation through a semi-empiric al model core potential. Data obtained extend and clarify considerably the classification of lines in the existing photoabsorption and eject ed-electron spectra of Na. Lifetime determination included radiative d ecay to the bound 2p6nl levels and to the lower core-excited states as well as autoionization. Both correlational and relativistic effects p lay an important role, as expected, but in addition it was found that the non-orthogonality of bound and continuum orbitals, being a result of core excitation, is also very important in evaluating of autoioniza tion rates. The predicted lifetimes are analysed with respect to their 'quasimetastability', which has recently attracted great attention in atomic spectroscopy and in the construction of XUV lasers.