Microscopy and Microanalysis

Software and Techniques Development

Compton Scattering Artifacts in Electron Excited X-Ray Spectra Measured with a Silicon Drift Detector

Nicholas W.M. Ritchiea1 c1, Dale E. Newburya1 and Abigail P. Lindstroma1

a1 National Institute of Standards and Technology, Gaithersburg, MD 20899, USA

Abstract

Artifacts are the nemesis of trace element analysis in electron-excited energy dispersive X-ray spectrometry. Peaks that result from nonideal behavior in the detector or sample can fool even an experienced microanalyst into believing that they have trace amounts of an element that is not present. Many artifacts, such as the Si escape peak, absorption edges, and coincidence peaks, can be traced to the detector. Others, such as secondary fluorescence peaks and scatter peaks, can be traced to the sample. We have identified a new sample-dependent artifact that we attribute to Compton scattering of energetic X-rays generated in a small feature and subsequently scattered from a low atomic number matrix. It seems likely that this artifact has not previously been reported because it only occurs under specific conditions and represents a relatively small signal. However, with the advent of silicon drift detectors and their utility for trace element analysis, we anticipate that more people will observe it and possibly misidentify it. Though small, the artifact is not inconsequential. Under some conditions, it is possible to mistakenly identify the Compton scatter artifact as approximately 1% of an element that is not present.

(Received November 17 2010)

(Accepted July 07 2011)

Correspondence:

c1 Corresponding author. E-mail: nicholas.ritchie@nist.gov

Footnotes

Disclaimer: Certain commercial equipment, instruments, or materials are identified in this article to foster understanding. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose.