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Nicholas Ritchie (Fed)

Physicist (2004 - Present)

Nicholas W. M. Ritchie had the pleasure of studying in Randall Hulet's laser trapping and cooling laboratory at Rice University. For his master's thesis, he contributed to our understanding of quantum measurements with the first experimental realization of a measurement of a "weak value" - a concept which had recently been proposed by Aharonov & Vaidman. For his doctorate, he built a magneto-optical trap and performed studies on trap loss mechanisms in magneto-optically trapped lithium atoms. He contributed to spectroscopic studies of weakly bound dilithium at millikelvin temperatures. After graduate school Nicholas spent almost a decade in commercial instrument development for Aspex Corporation. Here he designed and implemented the software for their flagship product and lead the development effort for their next-generation electronics package. The Aspex system remains the state-of-the-art scanning electron microscope for high speed automated particle analysis. In 2004, he left Aspex to join NIST. At NIST he has continued his interest in automated particle analysis and has taken on new interests in quantitative x-ray microanalysis. In particular, he has developed the NISTMonte Monte Carlo simulator of electron and x-ray transport. NISTMonte is now fully integrated into another of Nicholas' projects, DTSA-II - a system for quantitative x-ray microanalysis. With NISTMonte and DTSA-II, Nicholas hopes to provide the community with an open-source tool set which helps microanalysts make high quality measurements.


Fellow of the Microbeam Analysis Society

Selected Publications

Spectrum Simulation in DTSA-II

Nicholas W. Ritchie
Spectrum simulation is a useful practical and pedagogical tool. Particularly with complex samples or trace constituents, a simulation can help to understand the

Strategies for Standardizing EDS Measurements

Nicholas Ritchie
Energy dispersive X-ray spectrometers (EDS) are capable of precise and accurate electron beam measurements of composition. However, the optimal strategies for


The hazard of UV-induced oxidation to solar-viewing spacecraft optics

Charles S. Tarrio, Robert F. Berg, Thomas B. Lucatorto, Dale E. Newbury, Nicholas Ritchie, Andrew Jones, Frank Eparvier
The two most prevalent outgas contaminants on satellites are organic molecules and water vapor. Adsorbed organic molecules can degrade a solar-viewing
Created October 9, 2019, Updated March 17, 2023