Magnetically induced transition in the spectrum of Sr iv

Abstract

Observations and studies of what we call magnetic induced transitions have arguably re-opened a whole new area of atomic spectroscopy. There are transitions from upper levels that are sensitive to externally applied magnetic fields, such as those in tokamaks and the solar corona. So far only two types of ionic systems have been confirmed as leading to magnetic induced transitions, namely Ne-like Ar and Fe, and Cl-like Fe. We here propose a homologous system to Cl-like ions, namely Br-like ions, as a new candidate. These transitions are fed by close degeneracy between levels of relative short and long lifetimes, respectively. A similar close degeneracy as in Cl-like Fe is present in Br-like Sr and will give rise to an observable magnetic induced transition. We have predicted the magnetic induced transition rate for the ${}^{4}{D}_{7/2}$ level in Sr iv as a function of magnetic field strengths.