Laser Spectroscopy of Highly-Charged Ions


Helium-like ions are highly-charged ions where all the atomic electrons have been removed except two. Their structure is hence analogous to ordinary helium, but with a higher nuclear charge. The electrons have higher velocity and increased relativistic behavior. At FSU we have pursued a program of precision laser spectroscopy of helium-like ions. The purpose is to test ab initio atomic structure theory, based on quantum-electrodynamics of bound states. Interesting relativistic and QED effects scale rapidly with atomic number Z, and so can be sensitively investigated by performing measurements at different Z. Several atomic theory groups are engaged in this area, including those at the University of Notre Dame, Windsor (Canada), Lawrence Livermore, NIST Gaithersburg, Lund (Sweden), St. Petersburg (Russia), Warsaw (Poland), Dresden (Germany). As well as the intrinsic importance of testing fundamental atomic theory, our measurements have application to the program of obtaining an alternative value for the fine structure constant from precision spectroscopy of neutral helium.

Acknowledgement: This work was supported in part by the National Science Foundation.