- National Institute of Standards and Technology, Contractor, 2003-Present
- Apex Software, Inc., Senior Consultant, 2000-2003
- National Institute of Standards and Technology, Guest Researcher, 1994-1995
- Institute of Spectroscopy, Russian Academy of Science, Senior Scientific Researcher, 1981-2000
- American Physical Society, Member, 2000-Present
Moscow Institute of Physics and Technology, Ph.D. Quantum Radiophysics, 1984. Thesis Title: Identification of the 3s-3p and 3p-3d transitions of the neon-like ions S VII, Cl VIII, Ar IX and K X on the basis of spectra emitted by laser-produced plasmas.
Alexander is interested in the analysis of spectra of neutral and ionized atoms and is active in the critical compilation of atomic spectral data for NIST's atomic spectroscopy databases. He is currently involved in evaluation of energy levels, wavelengths, and transition probabilities in several spectra of atoms and atomic ions and critical evaluation of experimental and theoretical ionization energies of all stages of ionization of all chemical elements. Utilizing his knowledge of computer programming, he assists in support of the on-line databases on atomic spectra.