Measures for Spectral Quality in Low-Voltage X-Ray Microanalysis

Published

November 1, 2000

Author(s)

Dale E. Newbury

Abstract

Characteristic x-ray production with energetic electrons depends strongly on the overvoltage, the ratio of the incident beam energy to the critical excitation energy for the atomic species of interest. Low voltage x-ray microanalysis (beam energy < 5 keV) is expecially susceptible to artifacts due to sample charging because the overvoltage is low and evenslight charging can strongly affect peak intensities. The Duane-Hunt bremstrahlung limit is a good diagnostic to detect sample charging. Dynamic charging effects, however, can influence spectra despite an apparently satisfactory Duane-Hunt limit. Dynamic charging effects must be examined by time series experiments, or through use of dynamic energy windows continuously measuring count rates placed across the spectrum. When charging is a problem, conductive surface coatings can eliminate the effects. When pristine surfaces must be examined without coating, the use of a conductive grid can control charging so that useful x-ray spectra can be obtained.

Citation

Scanning

Volume

22

Issue

No. 6

Pub Type

Journals

Keywords

charging, conducting grid method, Duane-Hunt limit, electron beam x-ray microanalysis, overvoltage, x-ray spectrometry

Citation

Newbury, D. (2000), Measures for Spectral Quality in Low-Voltage X-Ray Microanalysis, Scanning (Accessed April 19, 2024)