Analysis of the competition between forbidden and hyperfine-induced transitions in Ne-like ions

In this work we investigate the decay of the vertical bar 2p(5) 3s P-3(0)> state in neon-like ions along the isoelectronic sequence ranging from Z = 10 to Z = 35. In the absence of a nuclear spin, the magnetic dipole transition to vertical bar 2p(5) 3s P-3(1)> is the dominating decay channel. However, for isotopes with a nuclear spin, the interaction between the nuclear magnetic dipole moment and the electronic field introduces a mixing of vertical bar 2p(5) 3s (3)P1 > and vertical bar P-1(1)> into the vertical bar P-3(0)> state, which in turn opens up a competing hyperfine-induced electric dipole decay channel to the ground state. This hyperfine-induced transition channel clearly dominates over the magnetic dipole channel for the neutral end of the isoelectronic sequence, when present. We give values for the rates of both these competing channels and discuss how the introduction of the hyperfine-induced transition channel could have a dramatic influence on the spectrum, not only because it introduces a new line, but also since it can substantially decrease the intensity of the magnetic dipole 2p(5) 3s P-3(0) -> 2p(5) 3s P-3(1) line and affect the predicted ionization balance in different plasmas.