Systematic theoretical study of dielectronic recombination for helium-like isoelectronic sequence

Dielectronic recombination cross sections and rate coefficients of He-like isoelectronic sequence are systematically calculated employing the relativistic Flexible Atomic Code (FAC). The calculated DR resonance strengths, cross sections and rate coefficients are in good agreement with other experimental and theoretical results. The effects of radiative cascades on DR cross sections and the variation of DR branching ratio with different DR resonance and atomic numbers Z are studied. The n−3 scaling law is also checked and used to extrapolate rate coefficients. And analytic formulas are used to fit the total rate coefficients with respect to both T and Z for helium-like isoelectronic sequence.