Applications of a Laboratory X-ray Micropsobe to Materials Analysis

1988 ◽  
Vol 32 ◽  
pp. 115-120 ◽  
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor ◽  
C. E. Holcombe
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Materials Analysis ◽  
X Ray ◽  
Small Glass

A laboratory-based X-ray microprobe, composed of a high-brilliance microfocus X-ray tube, coupled with a small glass capillary, has been developed for materials applications. Because of total external reflectance of X rays from the smooth inside bore of the glass capillary, the microprobe has a high sensitivity as well as a high spatial resolution. The use of X rays to excite elemental fluorescence offers the advantages of good peak-to-background, the ability to operate in air, and minimal specimen preparation. In addition, the development of laboratory-based instrumentation has been of Interest recently because of greater accessibility when compared with synchrotron X-ray microprobes.

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.

X-ray detection performance of a 300KV field-emission Analytical Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 250-251
Author(s):  
C. E. Lyman ◽  
J. I. Goldstein ◽  
D.B. Williams ◽  
D.W. Ackland ◽  
S. von Harrach ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Detection Performance ◽  
Electron Gun ◽  
X Rays ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope

A major goal of analytical electron micrsocopy (AEM) is to detect small amounts of an element in a given matrix at high spatial resolution. While there is a tradeoff between low detection limit and high spatial resolution, a field emission electron gun allows detection of small amounts of an element at sub-lOnm spatial resolution. The minimum mass fraction of one element measured in another is proportional to [(P/B)·P]-1/2 where the peak-to-background ratio P/B and the peak intensity P both must be high to detect the smallest amount of an element. Thus, the x-ray detection performance of an analytical electron microscope may be characterized in terms of standardized measurements of peak-to-background, x-ray intensity, the level of spurious x-rays (hole count), and x-ray detector performance in terms of energy resolution and peak shape.This paper provides measurements of these parameters from Lehigh’s VG Microscopes HB-603 field emission AEM. This AEM was designed to provide the best x-ray detection possible.

Versatile Lithium Fluoride Luminescent Detectors for High Resolution Imaging Applications from Extreme Ultraviolet to Soft and Hard X-Rays

2016 ◽  
Vol 98 ◽  
pp. 54-63
Author(s):  
Francesca Bonfigli ◽  
Enrico Nichelatti ◽  
Maria Aurora Vincenti ◽  
Rosa Maria Montereali
Keyword(s):  
Spatial Resolution ◽  
Lithium Fluoride ◽  
Dynamic Range ◽  
High Spatial Resolution ◽  
Extreme Ultraviolet ◽  
Large Field ◽  
X Rays ◽  
X Ray ◽  
Research Fields ◽  
X Ray Imaging

X-ray imaging represents a very relevant tool in basic and applied research fields due to the possibility of performing non-destructive investigations with high spatial resolution. We present innovative X-ray imaging detectors based on visible photoluminescence from aggregate electronic defects locally created in lithium fluoride (LiF) during irradiation. Among the peculiarities of these detectors, noteworthy ones are their very high spatial resolution (intrinsic ∼2 nm, standard ∼300 nm) across a large field of view (>10 cm2), wide dynamic range (>103) and their insensitivity to ambient light. The material photoluminescence response can be enhanced through the proper choice of reflecting substrates and multi-layer designs in the case of LiF films. The present investigation deals with the most appealing X-ray imaging applications, from simple lensless imaging configurations with commonly-available laboratory polychromatic X-ray sources to X-ray imaging-dedicated synchrotron beamlines in absorption and phase contrast experiments.

scholarly journals X-Ray Optics and Precision Requirements for Residual Stress Analyses with High Spatial Resolution

2014 ◽  
Vol 996 ◽  
pp. 228-233
Author(s):  
Bernd Eigenmann
Keyword(s):  
Residual Stress ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Small Diameter ◽  
Sample Surface ◽  
Glass Capillary ◽  
Ray Optics ◽  
X Ray ◽  
Small Spot ◽  
Stress Analyses

In recent years, the demand for high spatial resolution in X-ray residual stress analysis has drastically increased. The locations of interest are frequently small foot radii of teeth of gears. Also the inner surface of holes or hollow cylinders in general with small diameter must be investigated after opening the cylindrical cavities. In resolving such measuring problems, significant progress has been made in reproducibly manufacturing and applying glass capillary X-ray optics. With focusing elliptical polycapillaries and conventional laboratory X-ray sources, spot sizes of few 10 μm can be realized at sufficiently intensities for residual stress analyses. However, glass capillary optics require refined alignment strategies which are completely different from those for conventional beam shaping optics. Moreover, the small spot sizes cannot be aligned and positioned on the sample surface by eye. Microscopy fixtures are required. Finally, measurements in small radii result in high precision requirements for the diffractometers as well as for the sample positioning in axes and directions which are significantly less relevant when measuring on plane surfaces. The specific requirements resulting from residual stress analyses with high spatial resolution using glass capillaries and small spot sizes at curved surfaces are described and discussed.

scholarly journals Instrumentation for the Measurement of High Energy Phenomena on NASA Spacecraft

1971 ◽  
Vol 41 ◽  
pp. 134-134
Author(s):  
Albert G. Opp ◽  
Nancy G. Roman
Keyword(s):  
Spatial Resolution ◽  
Spectral Distribution ◽  
High Spatial Resolution ◽  
High Sensitivity ◽  
High Energy ◽  
Temporal Variations ◽  
X Ray ◽  
Sky Survey ◽  
Beryllium Window ◽  
Proportional Counters

High energy astrophysical observations supported by the National Aeronautics and Space Administration will be conducted primarily from the Small Astronomy Satellites (SAS) and the High Energy Astronomy Observatories (HEAO). At the present time, three Small Astronomy Satellites have been approved for flight. The first (SAS A) will carry a set of collimated proportional counters to conduct a high sensitivity, high spatial resolution, all sky survey for X-ray sources, to search for temporal variations in the source intensity, and to measure the spectral distribution of sources in the energy range 1 to 20 keV. The spacecraft will carry two collimator systems of 1 by 10 deg and 10 by 10 deg fullwidth. The proportional counters are gas-filled beryllium window tubes. SAS A is planned for launch in late 1970.

scholarly journals Coronal Transients in Radio and X-rays

1996 ◽  
Vol 154 ◽  
pp. 15-22
Author(s):  
Mukul R. Kundu
Keyword(s):  
Active Region ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
X Rays ◽  
Imaging Data ◽  
X Ray ◽  
Type Iii ◽  
Wave Data ◽  
Spatially Resolved ◽  
Radio Imaging

AbstractWe present a summary of several studies of transient coronal phenomena based upon high spatial resolution radio imaging data along with Yohkoh SXT and HXT observations. In addition to normal flares the studies also involve such exotic events as active region transient brightenings (ARTB) and coronal jets and bright points. We provide evidence of nonthermal processes in flaring X-ray bright points from spatially resolved meter-wave data, existence and propagation of type III burst emitting electrons in coronal jets, radio signatures of ARTB’s, and beaming of electrons producing microwave and hard X-rays. The implications of these observations are discussed.

scholarly journals High Spatial Resolution in X-Ray Fluorescence

1986 ◽  
Vol 30 ◽  
pp. 77-83
Author(s):  
John D. Zahrt
Keyword(s):  
Spatial Resolution ◽  
Amorphous Materials ◽  
High Spatial Resolution ◽  
Signal To Noise Ratio ◽  
Bragg Angle ◽  
X Rays ◽  
Bremsstrahlung Radiation ◽  
Signal To Noise ◽  
X Ray ◽  
The Past

During the past eight years or so there has been growing interest in using a polarized x-ray source in energy dispersive x-ray fluorescence spectrometers (1,2,3,4). The effect is to annihilate the source x rays before they scatter into the detector, thus significantly increasing the signal to noise ratio.Both characteristic or Bremsstrahlung radiation can be polarized by 90° scattering from crystals (Bragg angle = 45°) or from amorphous materials respectively. This 90° polarizing scatter event greatly reduces the incident source radiation on a sample. In an effort to regain some intensity use is made of concave surfaces to utilize a manifold of beams (5,6,7).

Materials science of cells: Electron probe x-ray microanalysis and x-ray mapping in biology

1989 ◽  
Vol 47 ◽  
pp. 238-239
Author(s):  
Andrew P. Somlyo
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Materials Science ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Ray ◽  
Low Concentrations ◽  
Freeze Dried ◽  
And Control

The general aims of Electron Probe X-ray Microanalysis (EPMA) in Biology is similar to that in Materials Science: the determination of composition at sub-micron resolution. Special requirements include stringent precautions for specimen preparation, high sensitivity for detecting low concentrations of elements avoidance, and if not possible, quantitation and control of radiation damage, and spatial resolution of at least tens of nanometers.Special precautions for specimen preparation are dictated by the fact that biological materials exist in an aqueous milieu, and one of the most common objectives of biological EPMA is the localization and quantitation of diffusible elements. Therefore, specimen preparatory techniques must include handling of live tissues in a manner that maintains normal physiological states, and rapid freezing to trap diffusible elements in their physiological compartments. In order to obtain high spatial resolution, ultrathin cryosections have to be obtained, freeze dried and transferred to the microscope under conditions that prevent elemental translocations. Specimen temperatures during cryo-sectioning are usually at about -100°centigrade.

X-ray film as a two-dimensional detector for X-ray diffraction analysis

2003 ◽  
Vol 18 (2) ◽  
pp. 91-98 ◽  
Author(s):  
T. N. Blanton
Keyword(s):  
Diffraction Analysis ◽  
Spatial Resolution ◽  
Diffraction Data ◽  
High Spatial Resolution ◽  
Silver Halide ◽  
X Rays ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Film Composition ◽  
X Ray

Silver halide based photographic imaging elements have been utilized as detectors for X-rays for over 100 years. These elements comprised of gelatin dispersed silver halide coated on one or both sides of a support, have been utilized in diffraction experiments since the discovery of X-ray diffraction by Laue and co-workers. X-ray film has high spatial resolution and can be adapted to flat or curved two-dimensional detection geometries. This paper describes the use of X-ray film as a two-dimensional detector for X-ray diffraction analysis, and discusses X-ray film composition, exposure, and processing, along with considerations for analyzing X-ray diffraction data collected using X-ray film.

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