The study of dielectronic recombination (DR) rate coefficient for ground state of Ne-like isoelectronic sequence ions

The dielectronic recombination (DR) rate coefficients for Ne-like isoelectronic sequence ions in the ground state 2s22p6 are calculated by using relativistic configuration interaction (RCI) method over a wide temperature ranging from 0.1EI to 10EI where EI is the ionization energy of corresponding Na-like ion. The (2s2p)73ln'l', (2s2p)74l4l' and (2s2p)74l5l' complexes are considered as autoionizing doubly excited states of Ne-like ions in the calculation. The contribution of (2s2p)73ln'l' complex with l' >8 is found to be negligible. The contribution of high Rydberg states of (2s2p)73ln'l' complex obeys the complex-complex n'-3 extrapolation, and the larger the nuclear charge, the smaller the value of n' is. On the basis of the detailed level-by-level results, a general analytic formula for the total DR rate coefficient for all the ions along the Ne-like isoelectronic sequence is constructed. This formula can generally reproduce the calculated DR rate coefficients within 2% for electron temperature between 0.1EI and 10EI. Burgess-Merts semiempirical formula is found to be inadequate for predicting the DR rates of Ne-like ions at low electron temperatures (kTeEI) and may be used for high electron temperatures (kTe > 2EI).