Photoionization of magnesium from the excited 3sndD1states to the doubly excited 3pnl1F autoionization states

We present the result of a theoretical estimation of the photoionization cross sections for transitions from the excited 3snd ${}_{}{}^1{}_{}{}^{}D$ states of Mg to the doubly excited 3pnl ${}_{}{}^1{}_{}{}^{}F$ autoionization states above the first ionization threshold. In particular, we examine in detail the effect of the multielectron interactions both in the initial and the final states of the transition. The calculated excitation energy and the width for the 3pnl${}^1$F autoionization series are reported. The experimental implications are also discussed.