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Yuri Ralchenko (Fed)

Group Leader

Dr. Yuri Ralchenko is the Leader of the Atomic Spectroscopy Group at NIST. His research is focused on spectroscopy of highly-charged ions, analysis of various atomic processes in plasmas with emphasis on accurate modeling of plasma population kinetics, development of Internet atomic databases, and other aspects of plasma and atomic spectroscopy. This work includes collisional-radiative modeling of various plasmas (including non-Maxwellian and transient ones), production and assessment of accurate atomic data (energies, oscillator strengths, collisional cross sections, etc.), and development of methods and standards for uncertainty quantification and dissemination of scientific data.

Dr. Ralchenko is an Editorial Board member of several scientific journals, has authored over 140 scientific publications, and has been a speaker at numerous national and international conferences. He also is a frequent consultant at the International Atomic Energy Agency (IAEA) and a co-director of a series of Schools on atomic and plasma spectroscopy organized jointly by IAEA and the International Centre for Theoretical Physics in Trieste, Italy.


2009: Fellow of the American Physical Society for "significant contributions to the relativistic theory of highly-charged ions and collisional-radiative modeling, and through creation of online codes and databases for the atomic physics community"

2015: NIST Judson C. French Award for "establishing the world's premier resource for atomic reference data, relied upon for everything from nuclear forensics to Hubble Space Telescope data analysis"

2022: NIST PML Excellence in Cooperation, Collaboration, and Teamwork Award for "for development and deployment of a unique wide-band high-resolution microcalorimeter for precise x-ray spectroscopy of highly-charged ions"

Selected Publications

Development of NIST Atomic Databases and OnlineTools

Yuri Ralchenko, Alexander Kramida
Over the last 25 years, the atomic standard reference databases and online tools developed at the National Institute of Standards and Technology (NIST) provide


Benford's law in atomic spectra and opacity databases

Yuri Ralchenko, Jean-Christophe Pain
The intriguing law of anomalous numbers, also named Benford's law, states that the significant digits of data follow a logarithmic distribution favoring the

The NIST Plan for Providing Public Access to Results of Federally Funded Research

Katherine E. Sharpless, Regina L. Avila, Ronald F. Boisvert, A Kirk Dohne, James Fowler, Rachel B. Glenn, Gretchen Greene, Robert Hanisch, Andrea Medina-Smith, Alan Munter, Julie Petrousky, Yuri Ralchenko, Carolyn D. Rowland, James A. St Pierre, Adam Wunderlich, Jon Zhang
In 2013 White House Office of Science and Technology Policy (OSTP) issued a memo, "Increasing Access to the Results of Federally Funded Scientific Research." In

Background and blended spectral line reduction in precision spectroscopy of EUV and x-ray transitions in highly charged ions

Yuri Ralchenko, Joseph N. Tan, Aung S. Naing, Galen O'Neil, Paul Szypryt, Dipti Dipti, Grant Mondeel, Roshani Silwal, Alain Lapierre, Steven Blundell, Gerald Gwinner, Antonio Camargo Villari, Endre Takacs
We report a method in EBIT spectral analysis that reduces signal from contaminant lines of 1 known or unknown origin. We utilize similar ion charge

Analysis of E3 Transitions in Ag-like High-Z Ions Observed with the NIST EBIT

Yuri Ralchenko, David La Mantia, Aung S. Naing, Paul Szypryt, Joseph N. Tan, Endre Takacs, Dipti Dipti, Yang Yang, Adam Hosier, Hunter Staiger
We report measurements and identification of the E3 4f$_7/2,5/2}$-5s$_1⁄2$ transitions and E1 allowed transitions in Ag-like W (Z=74), Re (Z=75), and Ir (Z=77)
Created March 16, 2019, Updated December 8, 2022