Stark Effect On The Lifetime Of Metastable Energy Level Of Atoms

When an atom is in the external electric field,its energy levels will be split and shifted.This effect is called Stark effect.Because the external electric field will destroys the spatial symmetry of the atomic system,which lead to the mixing of atomic states with different angular momentum and will also induce new transitions,which have a considerable impact on the lifetime of the atomic level,especially on the lifetime of the metastable energy level of the atom.The transition induced by the external electric field is called Stark-induced transition.Stark-induced transitions can be used for plasma density diagnostics.In addition,transition matrix elements of weak interaction can be determined by the interference effect between Stark-induced transitions and weak interaction transitions.We have studied Stark-induced transitions between the 2s-1s energy levels for hydrogen-like ions in the non-relativistic and relativistic frameworks,and discussed its variation along the isoelectronic sequence,providing a scaling law for more complex systems.Using the multiconfiguration Dirac-Hartree-Fock?MCDHF?method,we studied the Stark mixing in metastable states in beryllium-like ion,and calculated the Stark-induced transition probability from 2s2p ³P₀ metastable energy level to ground state of beryllium-like isoelectronic sequence.The present work is as follows:?1?We have studied Stark-induced transitions of hydrogen-like ions under the non-relativistic and relativistic frameworks by using perturbation theory.The mixing coefficients for hydrogen-like isoelectronic sequence?Z=1-92?and the scaling relation of Stark-induced transition probability between 2s-1s energy levels of hydrogen-like ions are given.The variation along the isoelectronic sequence is discussed,which provides a scaling law for more complex systems.?2?Using the multiconfiguration Dirac-Hartree-Fock?MCDHF?method,taking helium-like aluminum ion as an example,the Stark-induced transition probabilities from the metastable 1s2s ¹S₀ to the ground state 1s^{2 1}S₀ of helium-like ions is given.In addition,we also calculated the Stark induced transition probability from the metastable state 2s2p ³P₀ to the ground state 1s²2s^{2 1}S₀ for beryllium-like isoelectronic sequences?Z=6-92?.