An Introduction to Low Energy X-Ray and Electron Analysis

1969 ◽  
Vol 13 ◽  
pp. 1-25 ◽  
Author(s):  
Burton L. Henke
Keyword(s):  
Electron Spectroscopy ◽  
Auger Electron ◽  
Light Element ◽  
Low Energy ◽  
X Rays ◽  
Excitation Spectra ◽  
X Ray ◽  
Langmuir Blodgett ◽  
Electrostatic Analyzer ◽  
Introductory Review

This is an introductory review of the physics and applications of low energy x-rays and electrons in the 10-1000 ev region. The basic interactions of these radiations within matter are discussed and typical de-excitation spectra, fluorescent x-ray and photoAuger electron, are presented. Specific examples of spectrographic methods and instruments for the low energy region are described as “based upon the use of long-spaced, Langmuir-Blodgett type of multilayers for ultrasoft x-ray analysis and the use of the hemispherical electrostatic analyzer for photo-Auger electron spectroscopy. Some examples of spectrographic signal, signal/background, and resolution are presented for applications to light element fluorescence, valence emission band, and photo-Auger electron analysis. The special aspects of the low energy x-ray analysis of high temperature plasmas and of x-ray astronomical sources in general are described.

Some Recent Work in Low Energy X-Ray and Electron Analysis

1968 ◽  
Vol 12 ◽  
pp. 480-495 ◽  
Author(s):  
Burton L. Henke ◽  
Robert E. Lent
Keyword(s):  
Auger Electron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Surface Characterization ◽  
Fluorescence Analysis ◽  
Low Energy ◽  
Light Elements ◽  
X Ray ◽  
Langmuir Blodgett ◽  
Low Energy Electron

AbstractResearch is being conducted on low energy x-ray and electron physics and application in the 100-1000 eV region. Work on the optimization of fluorescence analysis for light elements, including the development of efficient dispersive systems as the multilayer analysers of the Langmuir-Blodgett type, has been continued. Along with the ultrasoft x-ray program has been one on photoelectron and Auger electron spectroscopy. An evaluation of the application of low energy electron spectroscopy for surface characterization is being made.

Atomic Structure and Spectra

2021 ◽  
pp. 68-146
Author(s):  
Kannan M. Krishnan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
X Rays ◽  
X Ray ◽  
Spatially Resolved ◽  
Excitation Processes ◽  
Shell Ionization

We review the structure of atoms to describe allowed intra-atomic electronic transitions following dipole selection rules. Inner shell ionization is followed by characteristic X-ray emission or non-radiative de-excitation processes leading to Auger electrons that involve three atomic levels. Photon incidence also results in characteristic photoelectron emission, reflecting the energy distribution of the electrons in the solid. We present details of laboratory and synchrotron sources of X-rays, and discuss their detection by wavelength or energy-dispersive spectrometers, as well as microanalysis with X-ray (XRF), or electron (EPMA) incidence. Characteristic X-ray intensities are quantified in terms of composition using corrections for atomic number (Z), absorption (A), and fluorescence (F). Electron detectors use electrostatic or magnetic dispersing fields; two common designs are electrostatic hemispheric or mirror analyzers. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), used for surface analysis, require ultra-high vacuum. AES is a weak signal, best resolved in a derivative spectrum, shows sensitivity to the chemical state and the atomic environment, provides a spatially-resolved signal for composition mapping, and can be quantified for chemical analysis using sensitivity factors. Finally, we introduce the basics of XPS, a photon-in, electron-out technique, discussed further in §3.

Low Energy X-Ray and Electron Absorption Within Solids (100-1500 ev Region)

1973 ◽  
Vol 17 ◽  
pp. 150-213 ◽  
Author(s):  
Burton L. Henke ◽  
Eric S. Ebisu
Keyword(s):  
Cross Sections ◽  
Energy Region ◽  
Auger Electron ◽  
Light Element ◽  
Low Energy ◽  
Interaction Cross Section ◽  
Interaction Coefficients ◽  
Element Analysis ◽  
X Ray ◽  
Precise Knowledge

AbstractQuantitative analysis by x-ray fluorescence and photoelectron and Auger electron analysis can be effectively extended through a precise knowledge of the total aad subshell photoionization cross sections. Light element and intermediate element analysis, as based upon K and L series fluorescence respectively, involve x-ray interactions in the low energy region, Optimized analysis for essentially all the elements by x-ray induced photoelectron and Auger electron spectroscopy involves both x-ray and electron interactions in the low energy region. Unfortunately, theory and measurement for interaction cross sections in this 100-1500 eV region are difficult, particularly for the heavier elements. Nevertheless, recent advances in experimental and computerized-theoretical techniques for the determination of low energy interaction coefficients do permit establishing appreciatly more complete tabulations of cross sections than are currently available in this energy region.In this paper, the types of interaction cross section data that are needed for quantitative x-ray and electron analysis are defined. Such data that are available from experiment and from theory are reviewed and compared. Some newer techniques for the measurement of cross sections are discussed. And finally, new “state of the art” tables are presented for the mass absorption coefficients of all of the elements and of some special laboratory materials. These are tabulated specifically for twenty-six of the most commonly applied characteristic wavelengths in the 8-110 A region and are based upon the best currently available theoretical and experimental data.

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