Soft x‐ray analysis system for reflection, secondary electron, and fluorescence spectroscopy

1989 ◽  
Vol 60 (7) ◽  
pp. 2219-2222 ◽  
Author(s):  
Y. Hirai ◽  
I. Waki ◽  
A. Momose ◽  
K. Hayakawa
Keyword(s):  
Fluorescence Spectroscopy ◽  
Secondary Electron ◽  
X Ray ◽  
Analysis System

Comparison of Several Sem Imaging Modes in Studying Intracellular Particulates in the Lung

1976 ◽  
Vol 34 ◽  
pp. 222-223
Author(s):  
J. L. Abraham ◽  
K. Miyai
Keyword(s):  
Electron Microscope ◽  
Secondary Electron ◽  
X Ray ◽  
Radiographic Contrast Medium ◽  
Radiographic Contrast ◽  
Distribution Mapping ◽  
Backscattered Electron ◽  
Sem Imaging ◽  
Analysis System ◽  
Scanning Electron

The scanning electron microscope (SEM) offers several signal modes, each of which may contain unique information about the specimen. In this paper we demonstrate and compare the merits of the familiar secondary electron (SE) mode, the backscattered electron (BSE) mode, and x-ray distribution mapping.Lungs of hamsters treated intratracheally with the radiographic contrast medium tantalum suspended in carboxymethyl cellulose were fixed with intratracheal buffered 2% glutaraldehyde. Blocks were razor cut to a few mm, dehydrated and critical point dried. The dried blocks were mounted on aluminum SEM studs and coated with carbon,, followed in some instances by gold/palladium (60/40). Examination at 20 kv and 45° specimen tilt was done in an Etec SEM with a solid state BSE detector and a Cambridge S4 SEM with an ORTEC energy dispersive x-ray analysis system.

Fluorescence Analysis Using an Si (Li) X-Ray Energy Analysis System With Low-Power X-Ray Tubes and Radioisotopes

1971 ◽  
Vol 15 ◽  
pp. 228-239
Author(s):  
G. R. Dyer ◽  
D. A. Gedcke ◽  
T. R. Harris
Keyword(s):  
Fluorescence Spectroscopy ◽  
Energy Analysis ◽  
Fluorescence Analysis ◽  
Low Noise ◽  
Ionization Chambers ◽  
X Ray ◽  
Carbon And Nitrogen ◽  
Intrinsic Resolution ◽  
Analysis System ◽  
Intrinsic Energy

X-ray fluorescence spectroscopy has been in use since the early days of the twentieth century, when Moseley confirmed the order of the chemical periodic table. However, fluorescence spectroscopy until recently has depended on diffraction methods to obtain sufficient resolution. Intrinsic resolution of ionization chambers, scintillation detectors, and proportional counters is inadequate for discrimination o f lines due to adjacent elements of low atomic number. The advent o f solid-state detectors, especially those using lithium-compensated silicon and low-noise electronics, has recently brought intrinsic energy resolution to the point where lines from adjacent elements as light as carbon and nitrogen can be resolved in theory; and detection of K radiation from elements as light as sodium is practical. Thus the solution to the long-standing problem of an adequate detector is at hand, and energy-dispersive spectrometers are now feasible.

Electron behavior in the gaseous environment of the ESEM chamber

1996 ◽  
Vol 54 ◽  
pp. 838-839 ◽  
Author(s):  
S.A. Wight
Keyword(s):  
Secondary Electron ◽  
High Vacuum ◽  
Beam Current ◽  
Chamber Pressure ◽  
Environmental Scanning ◽  
Carbon Block ◽  
Faraday Cup ◽  
X Ray ◽  
Gaseous Environment ◽  
Working Distance

Measurements of electrons striking the sample in the Environmental Scanning Electron Microscope (ESEM) are needed to begin to understand the effect of the presence of the gas on analytical measurements. Accurate beam current is important to x-ray microanalysis and it is typically measured with a faraday cup. A faraday cup (Figure 1) was constructed from a carbon block embedded in non-conductive epoxy with a 45 micrometer bore platinum aperture over the hole. Currents were measured with an electrometer and recorded as instrument parameters were varied.Instrument parameters investigated included working distance, chamber pressure, condenser percentage, and accelerating voltage. The conditions studied were low vacuum with gaseous secondary electron detector (GSED) voltage on; low vacuum with GSED voltage off; and high vacuum (GSED off). The base conditions were 30 kV, 667 Pa (5 Torr) water vapor, 100,000x magnification with the beam centered inside aperture, GSED voltage at 370 VDC, condenser at 50%, and working distance at 19.5 mm. All modifications of instrument parameters were made from these conditions.

scholarly journals Non-Invasive Technical Investigation of English Portrait Miniatures Attributed to Nicholas Hilliard and Isaac Oliver

Heritage ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 1165-1181
Author(s):  
Flavia Fiorillo ◽  
Lucia Burgio ◽  
Christine Slottved Kimbriel ◽  
Paola Ricciardi
Keyword(s):  
Fluorescence Spectroscopy ◽  
Scientific Methodology ◽  
Small Scale ◽  
Artistic Practice ◽  
X Ray ◽  
Non Invasive ◽  
Miniature Painting ◽  
Entire Career ◽  
Similarities And Differences ◽  
Victoria And Albert Museum

This study presents the results of the technical investigation carried out on several English portrait miniatures painted in the 16th and 17th century by Nicholas Hilliard and Isaac Oliver, two of the most famous limners working at the Tudor and Stuart courts. The 23 objects chosen for the analysis, spanning almost the entire career of the two artists, belong to the collections of the Victoria and Albert Museum (London) and the Fitzwilliam Museum (Cambridge). A non-invasive scientific methodology, comprising of stereo and optical microscopies, Raman microscopy, and X-ray fluorescence spectroscopy, was required for the investigation of these small-scale and fragile objects. The palettes and working techniques of the two artists were characterised, focusing in particular on the examination of flesh tones, mouths, and eyes. These findings were also compared to the information written in the treatises on miniature painting circulating during the artists’ lifetime. By identifying the materials and techniques most widely employed by the two artists, this study provides information about similarities and differences in their working methods, which can help to understand their artistic practice as well as contribute to matters of attribution.

scholarly journals Possible Pitfalls in the Analysis of Minerals and Loose Materials by Portable XRF, and How to Overcome Them

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Valérie Laperche ◽  
Bruno Lemière
Keyword(s):  
Fluorescence Spectroscopy ◽  
Laboratory Data ◽  
Data Sets ◽  
Light Elements ◽  
Portable Xrf ◽  
X Ray ◽  
Protective Films ◽  
The Matrix ◽  
Valuable Complement ◽  
Physical Effects

Portable X-ray fluorescence spectroscopy is now widely used in almost any field of geoscience. Handheld XRF analysers are easy to use, and results are available in almost real time anywhere. However, the results do not always match laboratory analyses, and this may deter users. Rather than analytical issues, the bias often results from sample preparation differences. Instrument setup and analysis conditions need to be fully understood to avoid reporting erroneous results. The technique’s limitations must be kept in mind. We describe a number of issues and potential pitfalls observed from our experience and described in the literature. This includes the analytical mode and parameters; protective films; sample geometry and density, especially for light elements; analytical interferences between elements; physical effects of the matrix and sample condition, and more. Nevertheless, portable X-ray fluorescence spectroscopy (pXRF) results gathered with sufficient care by experienced users are both precise and reliable, if not fully accurate, and they can constitute robust data sets. Rather than being a substitute for laboratory analyses, pXRF measurements are a valuable complement to those. pXRF improves the quality and relevance of laboratory data sets.

Suitability of the Compton-to-Rayleigh ratio in X-ray fluorescence spectroscopy: hydroxyapatite-based materials characterization

2019 ◽  
Vol 34 (5) ◽  
pp. 854-859 ◽  
Author(s):  
Sofia Pessanha ◽  
Sara Silva ◽  
Luís Martins ◽  
José Paulo Santos ◽  
João M. Silveira
Keyword(s):  
Fluorescence Spectroscopy ◽  
Materials Characterization ◽  
X Ray

In this work, we established a methodology for the analysis and characterization of hydroxyapatite-based materials using X-ray fluorescence.

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