Atomic Nuclear Charge Dependence of Dielectronic Recombination to Be-like Ions

The atomic nuclear charge ( Z ) dependence of the dielectronic recombination (DR) rate coefficient (α) to the O 4+ , Ne 6+ , Mg 8+ , P 11+ , Ar 14+ , Ca 16+ , V 19+ , Fe 22+ ions as well as the auger energy (Δ E ), the radiative transition probability ( Ar ), and the autoionization rate ( Aa ) for the Be-like ions is studied both in quality and quantity. For the calculation of the energy levels, Ar and Aa values, Cowan’s code is employed. As for the doubly excited states, 1s 2 3 lnl ' ( l = s, p, d) are considered as well as 1s 2 2p nl states. In the DR processes, at low Z , only the 1s 2 2p nl → 1s 2 2s nl and 1s 2 3p nl → 1s 2 2s nl processes give a significant contribution. While, at high Z , the 1s 2 3s(or d) nl → 1s 2 2p nl and 1s 2 2p nl → 1s 2 2p n ' l ' processes also become important. The dielectronic recombination rate coefficient to the final excited 1s 2 2s nl show weak Z -dependence, on the other hand, those to the final excited 1s 2 2p nl states have a strong Z -dependence.