U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Nicholas Ritchie (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 76

Quantification of STEM-in-SEM Energy Dispersive X-ray Spectra using Bulk Standards

November 9, 2023
Author(s)
Nicholas Ritchie, Andrew Herzing, Vladimir Oleshko
A quantification model which uses standard X-ray spectra collected from bulk materials to determine the composition and mass-thickness of single-layer and multi-layer unsupported thin- films is presented. The multi-variate model can be iteratively solved

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

March 2, 2023
Author(s)
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 instrument when they are cracked by ultraviolet radiation (UV) and become a light-absorbing layer of

Quantitative Electron-Excited X-ray Microanalysis with Low Energy L-Peaks

August 12, 2021
Author(s)
Dale E. Newbury, Nicholas Ritchie
Quantitative electron-excited X-ray microanalysis that follows the standards-based intensity ratio method produces accurate results and an analytical total near unity based upon extensive testing on known materials. This paper investigates a significant

Proposal: Let's Develop a Community Consensus K-ratio Database

August 30, 2020
Author(s)
Nicholas Ritchie, Dale E. Newbury, John Fournelle, Aurelien Moy, Heather Lowers, Anette von der Handt, Paul Carpenter, Emma Bullock, John Donovan
The electron excited microanalysis community is increasingly running into the limitations of its ability to derive accurate an composition from measured x-ray intensities. Many of these limitations could be mitigated if the standard matrix correction

Embracing Uncertainty: Modeling Uncertainty in EPMA - Part I

May 21, 2020
Author(s)
Nicholas Ritchie
This is the first in a series of articles which present a new framework for computing the uncertainty in electron excited X-ray microanalysis measurements. This article will discuss the framework and apply it to a handful of simple but useful sub