Theoretical investigations on magnetic field induced $2p^53s^3P_{0,2} - 2p^6^1S_0$ transitions in Ne-like ions without nuclear spin

Abstract

We report theoretical results for magnetic field induced $2p^53s^3P_{0,2} - 2p^6^1S_0$ E1 transitions in Ne-like ions with zero nuclear spin (I=0) between Mg III and Zn XXI as well as in Ne I. We demonstrate that it is important to include both ``perturber'' states $2p^53s^1P_1$ and $2p^53s^3P_1$ in order to produce reliable transition rates. Furthermore, we investigate the trends of the rates along the isoelectronic sequence of the $2p^53s^3P_{0,2} - 2p^6^1S_0$ transitions and their competition with the $2p^53s^3P_0 - 2p^53s^3P_1$ M1 and the $2p^53s^3P_2 - 2p^6^1S_0$ M2 decays. For the $2p^53s^3P_0$ state the magnetic field induced transition becomes the dominant decay channel for the light elements even in a relatively weak magnetic field, and it will therefore prove useful in diagnostics of the strength of magnetic fields in different plasmas. The influence of an external magnetic field on the lifetime of the $2p^53s^3P_2$ state is much smaller but still observable for the ions near the neutral end of the sequence. As a special case, the magnetic field effect on the lifetimes of $2p^53s^3P_{0,2}$ states of neutral $^{20}$Ne is discussed. It is found that the lifetimes are drastically reduced by a magnetic field, which may be an underlying reason for the discrepancies in the lifetime of the $2p^53s^3P_2$ state between experiment (14.73(14) s) and theory (17.63 s).