Photoelectron Spectrometry: A New Approach to X-Ray Analysis

1972 ◽  
Vol 16 ◽  
pp. 74-89 ◽  
Author(s):  
Manfred O. Krause
Keyword(s):  
Energy Range ◽  
Emission Spectra ◽  
Atomic Level ◽  
Energy Dispersive ◽  
New Technique ◽  
X Rays ◽  
Electron Spectrometer ◽  
New Approach ◽  
X Ray

AbstractPhotoelectron spectrometry is shown to be an excellent technique for the analysis of x rays in the ultrasoft and soft x-ray regions. X rays are converted into photoelectrons which are ejected from a suitable atomic level, and the photoelectrons are analyzed with an electron spectrometer. The method is energy dispersive, provides a resolution ranging from 0.1 eV at 20 eV to 1.1 eV at 3 keV, and gives well-defined intensity characteristics throughout the range. The energy range can be extended into the 10 keV decade. Properties of the new technique are discussed, compared with conventional techniques, and exemplified by a series of measurements which include determination of the emission spectra of M x rays of yttrium to rhodium, L x rays of zirconium, and the band structures of molybdenum and holmium.

scholarly journals Quantitative analysis by energy dispersive X-ray fluorescence by the transmission method applied to geological samples

1994 ◽  
Vol 51 (2) ◽  
pp. 197-206 ◽  
Author(s):  
S.M. Simabuco ◽  
V.F. Nascimento Filho
Keyword(s):  
Atomic Number ◽  
Energy Dispersive ◽  
X Rays ◽  
Geological Samples ◽  
Transmission Method ◽  
Absorption Effect ◽  
X Ray ◽  
Fundamental Parameters ◽  
Absorption Correction

Three certified samples of different matrices (Soil-5, SL-1/IAEA and SARM-4/SABS) were quantitatively analysed by energy dispersive X-ray fluorescence with radioisotopic excitation. The observed errors were about 10-20% for the majority of the elements and less than 10% for Fe and Zn in the Soil-5, Mn in SL-1, and Ti, Fe and Zn in SARM-4 samples. Annular radioactive sources of Fe-55 and Cd-109 were utilized for the excitation of elements while a Si(Li) semiconductor detector coupled to a multichannel emulation card inserted in a microcomputer was used for the detection of the characteristic X-rays. The fundamental parameters method was used for the determination of elemental sensitivities and the irradiator or transmission method for the correction of the absorption effect of characteristic X-rays of elements on the range of atomic number 22 to 42 (Ti to Mo) and excitation with Cd-109. For elements in the range of atomic number 13 to 23 (Al to V) the irradiator method cannot be applied since samples are not transparent for the incident and emergent X-rays. In order to perform the absorption correction for this range of atomic number excited with Fe-55 source, another method was developed based on the experimental value of the absorption coefficients, associated with absorption edges of the elements.

Routine Determination of X-Ray Detector Efficiencies Using Submicron Spheres of Pure Materials

1985 ◽  
Vol 43 ◽  
pp. 416-417
Author(s):  
Thomas F. Kelly
Keyword(s):  
Electron Microscope ◽  
Energy Range ◽  
Transmission Electron Microscope ◽  
Weight Fraction ◽  
Characteristic Line ◽  
X Rays ◽  
Detector Efficiency ◽  
X Ray ◽  
Transmission Electron

The purpose of this paper is to outline an approach to routine determination of x-ray detector efficiencies over the entire applicable energy range that may be used on any transmission electron microscope.BACKGROUNDThe quantification of x-ray intensities using the ratio technique can be accomplished [see, for example, 1] using a relation of the form:Here, for element A, CA is the composition in the sample as a weight fraction, kA is the x-ray generation constant (see below) which contains only sample-dependent information, eA is the detector efficiency for characteristic x-rays which contains only detector-dependent information, and lA is the measured x-ray intensity in a characteristic line.

Oxford HEXameter: Laboratory High Energy X-Ray Diffractometer for Bulk Residual Stress Analysis

2006 ◽  
Vol 524-525 ◽  
pp. 743-748 ◽  
Author(s):  
Alexander M. Korsunsky ◽  
Shu Yan Zhang ◽  
Daniele Dini ◽  
Willem J.J. Vorster ◽  
Jian Liu
Keyword(s):  
Accurate Determination ◽  
High Energy ◽  
Energy Dispersive ◽  
Detector Response ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Instrument ◽  
Synchrotron Beamlines

Diffraction of penetrating radiation such as neutrons or high energy X-rays provides a powerful non-destructive method for the evaluation of residual stresses in engineering components. In particular, strain scanning using synchrotron energy-dispersive X-ray diffraction has been shown to offer a fast and highly spatially resolving measurement technique. Synchrotron beamlines provide best available instruments in terms of flux and low beam divergence, and hence spatial and measurement resolution and data collection rate. However, despite the rapidly growing number of facilities becoming available in Europe and across the world, access to synchrotron beamlines for routine industrial and research use remains regulated, comparatively slow and expensive. A laboratory high energy X-ray diffractometer for bulk residual strain evaluation (HEXameter) has been developed and built at Oxford University. It uses a twin-detector setup first proposed by one of the authors in the energy dispersive X-ray diffraction mode and allows simultaneous determination of macroscopic and microscopic strains in two mutually orthogonal directions that lie approximately within the plane normal to the incident beam. A careful procedure for detector response calibration is used in order to facilitate accurate determination of lattice parameters by pattern refinement. The results of HEXameter measurements are compared with synchrotron X-ray data for several samples e.g. made from a titanium alloy and a particulate composite with an aluminium alloy matrix. Experimental results are found to be consistent with synchrotron measurements and strain resolution close to 2×10-4 is routinely achieved by the new instrument.

Energy-Dispersive X-Ray Techniques for Accurate Heavy Element Assay

1986 ◽  
Vol 30 ◽  
pp. 285-292 ◽  
Author(s):  
H. Ottmar ◽  
H. Eberle ◽  
P. Matussek ◽  
I. Michel-Piper
Keyword(s):  
Absorption Edge ◽  
Heavy Element ◽  
Accurate Determination ◽  
Energy Dispersive ◽  
X Rays ◽  
Specific Absorption ◽  
X Ray ◽  
Xrf Analysis ◽  
Analysis Technique

Energy-dispersive X-ray techniques can be employed in two different ways for the accurate determination of element concentrations in specimens: (1) spectrometry of fluoresced characteristic X-rays as widely applied in the various modes of the traditional XRF analysis technique, and (2) spectrometry of the energy-differential transmittance of an X-ray continuum at the element-specific absorption-edge energies.

A Secondary-Source, Energy-Dispersive X-Ray Spectrometer and its Application to Quantitative Analytical Chemistry

1973 ◽  
Vol 17 ◽  
pp. 571-583
Author(s):  
R. P. Larsen ◽  
J. O. Karttunen
Keyword(s):  
Background Radiation ◽  
Energy Dispersive ◽  
Excitation Source ◽  
Secondary Source ◽  
X Rays ◽  
X Ray ◽  
Secondary Sources ◽  
The Individual ◽  
Detection Instrument

AbstractAn energy-dispersive X-ray spectrometer that (1) uses as the primary excitation source the power supply and tungsten X-ray tube from a conventional crystal spectrometer (General Electric XRD-6) and (2) uses as the secondary excitation source elemental metal foils that are readily interchangeable has been built and operated. The use of an X-ray tube with a high-voltage capability, 75 kilovolts max, enables the determination of elements with atomic numbers as high as 66 (terbium) to be based on the K series of X-rays; the highpower capability, 3.7 kilowatts max, enables a particularly intense beam of X-rays to be generated by the secondary source and hence, provides a particularly high detection capability for trace elements in a sample. An instrument that uses interchangeable secondary sources to irradiate the samples has several advantages over those instruments in which excitation is accomplished by direct irradiation with an X-ray tube: (1) the background radiation in the energy range where the X-rays of interest are measured is several orders of magnitude lower and is very uniform and (2) the energy of the excitation radiation can be closely matched to the absorption edges of the elements of interest in the sample.In the application of the instrument, particular emphasis has been placed on the development of tectmiques that will enable an energy-dispersive X-ray spectrometer to be used as the detection instrument for quantitative elemental analysis. Methods for the determination of the individual rare earths, plutonium and uranium at the microgram level with an accuracy of ± 1% are outlined and for the determination of plutonium and uranium at the milligram level with an accuracy of ± 0.1% are proposed.

Twenty Years of Progress in X-Ray Diffraction Techniques

1961 ◽  
Vol 5 ◽  
pp. 1-12
Author(s):  
Andre Guinier
Keyword(s):  
Electron Microscopy ◽  
List Type ◽  
X Rays ◽  
Type Number ◽  
Rational Utilization ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
Near Future

AbstractAlthough no revolutionary advance has been achieved in the last two decades, X-ray diffraction is not to be considered as a quiescent field of physics. Actually many improvements, in theory as well as in experiment, slight by themselves but very numerous, have considerably increased the efficiency of techniques such as the determination of crystal structures, the analysis of crystalline phases, and the applications of X-rays to various problems of the physics of solids. Only the two last points will be dealt with here:1.Crystalline phase analysis. The development of a satisfactory atlas of powder patterns has been too slow, and the data are not yet complete and precise enough to permit a rational utilization of the modern diffractometers. A very interesting new approach is the systematic indexing of the powder patterns which would be possible with computers. In the near future, anyone should be able to analyze a powder at any temperature as an easy routine experiment.2.The study of lattice defects. X-ray techniques are now in competition with electron microscopy, the development of which has been very successful in recent years. Now we have a better understanding of the possibilities of both techniques. X-rays give better results to determine the statistics of an extended disorder even if it is slight (e.g., degrees of order in a solid solution), and the microscope is more powerful for the detection of large but rare defects (e.g., dislocations).

scholarly journals ANALYSIS OF SUBMICROSCOPIC STRUCTURES BY THEIR EMITTED X-RAYS

1973 ◽  
Vol 21 (6) ◽  
pp. 580-586 ◽  
Author(s):  
E. W. DEMPSEY ◽  
F. J. AGATE ◽  
M. LEE ◽  
M. L. PURKERSON
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Semiconductor Detector ◽  
Emission Spectra ◽  
Energy Dispersive ◽  
X Rays ◽  
Sodium Potassium ◽  
X Ray ◽  
Copper Zinc ◽  
Scanning Electron

X-ray emission spectra have been recorded from several biologic tissues using a multichannel energy-dispersive analyzer with a retractible semiconductor detector coupled to a Cambridge Mark II scanning electron microscope. Particular attention has been given to the detection of silver in experimental argyria, of calcium in dermoid scales and in experimental necrosis of the kidney and of sulfur in the inner and outer portions of reptilian skin. Sulfur and chlorine have been found associated with silver in argyria. Phosphorus was associated with calcium both in the dermal scales and in necrotic areas. In addition to these elements, trace amounts of copper, zinc, lead, sodium, potassium, iron, arsenic, osmium and uranium have been detected in various normal and experimental situations. The applicability of the combined instrument to cytochemical problems is briefly discussed.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

Problems in Thin-Film X-ray Quantification

1990 ◽  
Vol 48 (2) ◽  
pp. 458-459
Author(s):  
J N Chapman ◽  
W A P Nicholson
Keyword(s):  
Thin Film ◽  
Specimen Thickness ◽  
X Rays ◽  
Characteristic Peak ◽  
Local Composition ◽  
X Ray ◽  
Measured Ratio ◽  
Path Lengths ◽  
Composition Changes

Energy dispersive x-ray microanalysis (EDX) is widely used for the quantitative determination of local composition in thin film specimens. Extraction of quantitative data is usually accomplished by relating the ratio of the number of atoms of two species A and B in the volume excited by the electron beam (nA/nB) to the corresponding ratio of detected characteristic photons (NA/NB) through the use of a k-factor. This leads to an expression of the form nA/nB = kAB NA/NB where kAB is a measure of the relative efficiency with which x-rays are generated and detected from the two species.Errors in thin film x-ray quantification can arise from uncertainties in both NA/NB and kAB. In addition to the inevitable statistical errors, particularly severe problems arise in accurately determining the former if (i) mass loss occurs during spectrum acquisition so that the composition changes as irradiation proceeds, (ii) the characteristic peak from one of the minority components of interest is overlapped by the much larger peak from a majority component, (iii) the measured ratio varies significantly with specimen thickness as a result of electron channeling, or (iv) varying absorption corrections are required due to photons generated at different points having to traverse different path lengths through specimens of irregular and unknown topography on their way to the detector.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

Sign in / Sign up

Export Citation Format

Share Document