scholarly journals X-Ray Fluorescence Analysis Applied to Small Samples

1977 ◽  
Vol 21 ◽  
pp. 171-185 ◽  
Author(s):  
J.M. Jaklevic ◽  
W.R. French ◽  
T.W. Clarkson ◽  
M.R. Greenwood
Keyword(s):  
Small Diameter ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Sample Volume ◽  
Small Sample ◽  
Small Samples ◽  
X Ray ◽  
Hair Samples ◽  
Fine Focus ◽  
Analysis System

We describe an adaptation of photon excited x-ray fluorescence analysis which is optimized for the analysis of small samples. A fine focus x-ray tube is used in conjunction with small diameter detector collimators in order to focus on a small sample volume with as high sensitivity as possible. Sample areas of less than 1 mm diameter can be analyzed with ppm detectability. In applications involving the analysis of human hair samples, a minimum detectable limit of 10 ppm Hg can be realized in a 1 mm long segment of a single hair in a counting time of 200 seconds. Simultaneous measurements of the sample mass can be obtained from the intensity of the incoherent scattering. An automated x-ray fluorescence analysis system using the technique for the scanning of elemental profiles in such hair samples will be described.

An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

1992 ◽  
Vol 50 (2) ◽  
pp. 1758-1759
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Close Coupling ◽  
X Ray ◽  
Point To Point ◽  
Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

An Improved X-Ray Fluorescence Method for the Analysis of Museum Objects

1969 ◽  
Vol 13 ◽  
pp. 94-104
Author(s):  
Maurice E. Salmon
Keyword(s):  
Critical Thickness ◽  
Alloy Composition ◽  
Fluorescence Analysis ◽  
Small Samples ◽  
Effective Absorption Coefficient ◽  
X Ray ◽  
Effective Absorption ◽  
Characteristic Wavelength ◽  
Museum Objects ◽  
Quantitative Results

A method is described for the x-ray fluorescence analysis of small samples, taken from museum objects, to determine alloy composition. The samples are dissolved in an appropriate reagent and absorbed on cellulose powder. The resulting powder is formed into a film of less than critical thickness and the effective absorption of the sample for the characteristic wavelength of the element being measured is determined. The effective absorption coefficient is used to correct the observed intensities in order to obtain quantitative results.

X-Ray Study of Pd40Cu30Ni10P20 Bulk Metallic Glass Brazing Filler for Ti-6Al-7Nb Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 1983-1987 ◽  
Author(s):  
E. Miura ◽  
Gene E. Ice ◽  
E.D. Specht ◽  
J.W.L. Pang ◽  
Hidemi Kato ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Depth Profiling ◽  
Fluorescence Analysis ◽  
Small Sample ◽  
Second Phase ◽  
X Ray ◽  
Fluorescence Measurements ◽  
Mechanical Bond ◽  
Grain Distribution

Crystalline precipitates in a bulk-metallic-glass (BMG) braze were investigated with an intense x-ray microbeam. The precipitates were found in the Pd40Cu30P20Ni10 BMG braze matrix after joining crystalline Ti-6Al-7Nb. However, the role (if any) played by the precipitates in improving the mechanical bond of the BMG/crystalline joint is unknown. X-ray microdiffraction and microfluorescence measurements from small sample volumes were made with an ~ 0.5 x 0.5 μm2 beam. Spatially-resolved Laue diffraction and x-ray fluorescence measurements were made on several second-phase crystals within the BMG matrix. Although precipitate crystals with the observed compositions were anticipated to be predominantly hexagonal, one of the crystals was found to be cubic or tetragonal. The instrumentation includes capabilities for 3D depth-resolved measurements of crystal structure and for fluorescence analysis of elemental composition. Depth profiling gave information about the grain distribution and morphology in the BMG matrix.

Micro-Analysis by X-Ray Absorption, Fluorescence, Emission and Diffraction Using Ultra-Fine X-Ray Sources

1957 ◽  
Vol 1 ◽  
pp. 329-337 ◽  
Author(s):  
V. E. Cosslett ◽  
P. Duncumb ◽  
J. V. P. Long ◽  
W. G. Nixon
Keyword(s):  
Line Emission ◽  
Fluorescence Emission ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Characteristic Line ◽  
X Rays ◽  
Emission Analysis ◽  
Thin Sections ◽  
X Ray ◽  
Micro Analysis

AbstractFine focus X-ray tubes developed for projection X-ray microscopy can also be used for X-ray micro-analysis. Areas about 10 microns in diameter of thin sections have been analyzed by measuring differences in X-ray transmission, with particular reference to the determination of calcium in biological materials and in minerals. The high intensity of this X-ray point source has permitted micro-fluorescence analysis of similar small areas with high sensitivity and reasonable time. The same electron optical system has been used for micro-emission analysis of rock slices and mineral grains. By scanning the electron beam over the specimen surface and recording either the scattered electrons or the emitted X-rays, a two-dimensional picture can be displayed of the physical features or of the distribution of a particular element respectively. The analysis of a selected, volume of 1 cubic micron in the surface has been obtained by plotting the characteristic line emission spectrum with a crystal spectrometer and proportional counter. The sensitivity is 0. 1% or 10−1 gram. Micro-beam X-ray diffraction has also been used with a stationary X-ray source both for transmission and back reflection with a 10 minute exposure from a 10 micron diameter area.

A Focusing System for X-ray Diffraction Studies of Materials Under High Pressure in the Diamond Cell

1990 ◽  
Vol 34 ◽  
pp. 437-446 ◽  
Author(s):  
Y. Wu ◽  
A. C. Thompson ◽  
J. H. Underwood ◽  
H. K. Mao ◽  
Y. W. Fei ◽  
...  
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Sample Volume ◽  
Small Samples ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultra High Pressure ◽  
High Pressure Studies ◽  
Invaluable Tool ◽  
Spherical Mirrors

Recent advances in techniques to generate static ultra-high pressure (>100 GPa) in the diamond anvil cell have significantly enhanced our understanding of the properties of solids under these extreme conditions. In order to characterize the structure of solids at these pressures, X-ray diffraction using synchrotron radiation has become an invaluable tool. Since the highest pressures are attained at the expense of sample volume (~ 100 μm3) , it is best to use the intense radiation available from a synchrotron to study the very small samples used in ultra-high pressure studies. Even with the intense x-ray beams currently available, it is still often desirable to focus the x-ray beam to increase the available flux. We have developed a focusing system which uses multilayer coated spherical mirrors. With this system, intense x-ray beams with sizes smaller than 10 μm by 10 μm can be achieved at a synchrotron radiation beamline. Previously, we used the focusing system for x-ray microprobe experiments.

scholarly journals Dual-comb Photothermal Spectroscopy

2021 ◽  
Author(s):  
Qiang Wang ◽  
Zhen Wang ◽  
Hui Zhang ◽  
Shoulin Jiang ◽  
Yingying Wang ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Spectroscopic Method ◽  
High Sensitivity ◽  
Fast Response ◽  
Sample Volume ◽  
Small Sample ◽  
Probe Laser ◽  
Spectral Measurements ◽  
Photothermal Spectroscopy ◽  
Fine Resolution

Abstract Dual-comb spectroscopy (DCS) has revolutionized optical spectroscopy by providing broadband spectral measurements with unprecedent resolution and fast response. Photothermal spectroscopy (PTS) offers an ultrasensitive and background-free gas sensing method, which is normally performed using a single-wavelength pump laser. The merging of PTS with DCS may enable a new spectroscopic method by taking advantage of both technologies, which has never been studied yet. Here, we report dual-comb photothermal spectroscopy (DC-PTS) by passing dual combs and a probe laser through a gas-filled anti-resonant hollow-core fiber, where the generated multi-heterodyne modulation of the refractive index is sensitively detected by an in-line interferometer. As an example, we have measured photothermal spectra of acetylene over 1 THz, showing a good agreement with the spectral database. Our proposed DC-PTS provides new opportunities for broadband gas sensing with super-fine resolution and high sensitivity, as well as with a small sample volume and compact configuration.

Development of an online X-ray fluorescence analysis system for heavy metals measurement in cement raw meal

2015 ◽  
Vol 49 (3) ◽  
pp. 188-193 ◽  
Author(s):  
Shan Qing ◽  
Zhang XinLei ◽  
Zhang Yan ◽  
Jia WenBao ◽  
Ling YongSheng ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fluorescence Analysis ◽  
X Ray ◽  
Analysis System
Sign in / Sign up

Export Citation Format

Share Document