Testing the Time Dependence of Fundamental Constants in the Spectra of Multicharged Ions

Abstract

A new method for measuring a possible time dependence of the fine-structure constant ($\alpha$) is proposed. The method is based on the level-crossing in two-electron highly-charged ions facilitating resonance laser measurements of the distance between the levels at the point of crossing. This provides an enhancement factor of about $10^{3}$ in Helium-like Europium and thus reduces the requirements for the relative accuracy of resonance laser measurements at about $10^{-12}$.