Scanning X-Ray Analytical Microscope using X-Ray Guide Tube

1991 ◽  
Vol 35 (B) ◽  
pp. 1289-1293
Author(s):  
Shuichi Shimomura ◽  
Hiromoto Nakazawa
Keyword(s):  
Thin Section ◽  
Small Area ◽  
Total External Reflection ◽  
Guide Tube ◽  
X Rays ◽  
Glass Capillary ◽  
X Ray ◽  
Plane Normal

AbstractA scanning X-ray analytical microscope was constructed using X-ray guide tube(XGT). XGT is a glass capillary which guides and focuses x-rays by total external reflection at the inner wall. The nature of X-ray beam passed through XGT is varied depending on the form of XGT. The cylindrical and conical types were used for the present setup. A small area (10μm × 10μm) of the sample was irradiated by the X-ray microbeam formed by XGT. Fluorescent and diffracted X-rays from the small area were detected by SSD. By scanning the sample in the plane normal to the X-ray microbeam, the intensity distributions of such secondary x-rays were measured and used as picture elements for constructing x-ray mapping images. The sample was a thin-section of an old chinaware. The images suggest a wide application of this instrument.

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.

scholarly journals Исследование этапов превращения кремния в карбид кремния в процессе атомного замещения методами полного внешнего отражения рентгеновских лучей и рентгеновской дифрактомерии

2022 ◽  
Vol 64 (3) ◽  
pp. 326
Author(s):  
С.А. Кукушкин ◽  
А.В. Осипов ◽  
Е.В. Осипова ◽  
В.М. Стожаров
Keyword(s):  
Structural Quality ◽  
Total External Reflection ◽  
X Rays ◽  
Reflection Method ◽  
X Ray Diffraction ◽  
Modified Technique ◽  
Substitution Method ◽  
X Ray ◽  
Sic Films

X-ray diffraction and total external reflection of X-rays (X-ray reflectometry) methods were used to study the successive stages of synthesis of epitaxial SiC films on Si (100) X-ray diffraction and total external X-ray reflection (XRD) methods were used to study successive stages of synthesis of epitaxial SiC films on Si (100) surfaces, (110) and (111) surfaces by the atom substitution method. The data on the transformation evolution of (100) surfaces were studied, (110) and (111) Si, into SiC surfaces. A comparative analysis of the X-ray structural quality of the SiC layers grown on Si by the atom substitution method with the quality of SiC layers grown by Advanced Epi by the standard CVD method. A modified technique for the total outer X-ray reflection method, based on measurements of the intensity of the reflected X-rays using a special parabolic mirror. It is shown that the method of total external reflection method makes it possible to obtain important information about the degree of surface roughness of SiC layers, the evolution of their crystal structure and plasmon energy in the process of Si to SiC conversion.

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.

Overview of polycapillary X-ray optics

2002 ◽  
Vol 17 (2) ◽  
pp. 70-80 ◽  
Author(s):  
Paul J. Schields ◽  
David M. Gibson ◽  
Walter M. Gibson ◽  
Ning Gao ◽  
Huapeng Huang ◽  
...  
Keyword(s):  
Focal Spot ◽  
State Of The Art ◽  
Substantial Reduction ◽  
Spot Size ◽  
Source Size ◽  
Total External Reflection ◽  
X Rays ◽  
Focal Spot Size ◽  
Polycapillary Optics ◽  
X Ray

Polycapillary optics are utilized in a wide variety of applications and are integral components in many state of the art instruments. Polycapillary optics operate by collecting X-rays and efficiently propagating them by total external reflection to form focused and parallel beams. We discuss the general parameters for designing these optics and provide specific examples on balancing the interrelations of beam flux, source size, focal spot-size, and beam divergence. The development of compact X-ray sources with characteristics tailored to match the requirements of polycapillary optics allows substantial reduction in size, weight, and power of complete X-ray systems. These compact systems have enabled the development of portable, remote, and in-line sensors for applications in industry, science and medicine. We present examples of the utility and potential of these optics for enhancing a wide variety of X-ray analyses.

Protein Crystallography Using Capillary-Focused X-Rays

1996 ◽  
Vol 54 ◽  
pp. 238-239
Author(s):  
D. X. Balaic ◽  
Z. Barnea ◽  
K. A. Nugent ◽  
R. F. Garrett ◽  
J. N. Varghese ◽  
...  
Keyword(s):  
Fluorescence Analysis ◽  
Focal Region ◽  
X Rays ◽  
Glass Capillary ◽  
Synchrotron Source ◽  
X Ray ◽  
Exit Aperture ◽  
Egg White Lysozyme ◽  
Diffraction Patterns ◽  
Focused Beam

Tapered glass capillaries for X-ray beam concentration have been a topic of much interest for the synchrotron X-ray community in recent years. These optics have long held the promise of high-intensity microbeam generation for the “hard” X-ray energies used in crystallography and fluorescence analysis.X-ray concentration is achieved by exploiting the total external reflection property of glass surfaces for glancing angles of incidence. X-rays directed into the entrance aperture of the capillary are reflected toward an exit aperture of smaller dimensions, resulting in an increased X-ray flux per unit area at the exit aperture. Capillary designs with a true geometrical focus beyond the capillary exit are also possible.Our group has recently demonstrated a paraboloidally-tapered glass capillary optic which produced a focused X-ray beam using a monochromatised synchrotron source. The optic was designed to produce a focal region for singly-reflected X-rays at a point 40 mm from the end of the capillary. Such a focal region was observed, with a FWHM intensity gain of two orders of magnitude over the incident X-ray intensity from the channel-cut monochromator. Moreover, this gain was achieved for X-ray energies from 5 to 20 keV. We subsequently used a similar optic to obtain X-ray diffraction patterns from a crystal of hen egg-white lysozyme on image plates. The use of the capillary-focused beam yielded diffraction patterns 70 to 100 times faster than using an unfocused beam from the channel-cut monochromator alone. Placement of the crystal at different positions in the capillary-focused beam demonstrated the focusing of Bragg reflections and diffraction from a small volume of crystal.

X-ray Capillary Microbeam Spectrometer

1989 ◽  
Vol 33 ◽  
pp. 623-628 ◽  
Author(s):  
S. Larsson ◽  
P. Engstrom ◽  
A. Rindby ◽  
B. Stocklassa
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Optical Microscope ◽  
X Rays ◽  
Glass Capillary ◽  
Capillary Tubes ◽  
X Ray

AbstractBy utilizing the total reflecting properties of x-rays inside glass capillary tubes, intensive fine- or microbeams of x-rays can be attained. By using a conventional x-ray tube in combination with capillary technique, microbeams with a diameter of a few μm and with an intensity sufficient for trace elements, analyses have been achieved. By moving the sample, lineand areascan can be performed and trace element information can be directly superimposed on a micrograph from a built-in optical microscope.The background of the capillary technique is reviewed and an EDXRF microbeam spectrometer for trace elements is described. Examples of applications for the microbeam spectrometer are given.

Developments in Analytical Diffraction Using Isotopic X-Ray Sources

1970 ◽  
Vol 14 ◽  
pp. 139-145
Author(s):  
W. S. Toothacker ◽  
L. E. Preuss
Keyword(s):  
Exposure Time ◽  
Specific Activity ◽  
X Rays ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Oak Ridge ◽  
Position Sensitive ◽  
Diffraction Patterns ◽  
Intense Source

AbstractLobov et al., in Leningrad, and workers at this laboratory have been working on the idea of using x rays from radioactive sources for x ray diffraction analysis. The Russians have been using iron-55 produced by the (n, Y) reaction in their work with a small focusing camera which operates in the back reflection region. We have been using iron-55 produced by the (p,n) reaction in conjunction with a small Debye-Scherrer camera. The preliminary work of this laboratory was reported at this conference two years ago. At that time a 13 mCi iron-55 source was used in a two inch diameter Debye-Scherrer camera to obtain x-ray diffraction patterns of LiF. The exposure times were of the order of 120 hours and the reflection from the 200 plane was about 3 degrees wide. Since that time a new and more intense source has been constructed at Oak Ridge National Laboratories. With the new source it was possible to produce LiF diffraction patterns of the same density and resolution as before in a period of less than ten hours.The above mentioned diffraction patterns were made with the LiF powder placed in a 1.0 mm diameter glass capillary. After reduction of the glass capillary diameter to 0.5 mm and appropriate reduction of the collimator width, we were able to improve the resolution considerably with no accompanying reduction in line density. The LiF patterns obtained in this way required an exposure time of about 20 hours and the width of the reflection from the 200 plane has been reduced to about 1.5 degrees.Hence we are able to report a reduction in exposure time from 116 hours to 20 hours and an increase in resolution by a factor of two over the data reported here two years ago. Thus the concept of using x rays from an isotope for powder diffraction has changed from a laboratory curiosity into a technique with practical possibilities. Both sources mentioned above were produced by the (p, n) reaction. The 135 mCi source had a specific activity of about 400 Ci/gm. Since iron-55 sources have been made with specific activities of about 1000 Ci/gm, a considerable decrease in exposure time could be accomplished by using such a source. The application to this work of a position sensitive proportional counter as developed by Semmler will also be discussed.

X-ray guide tube for diffraction experiments

1983 ◽  
Vol 16 (2) ◽  
pp. 239-241 ◽  
Author(s):  
H. Nakazawa
Keyword(s):  
Photon Energy ◽  
Glass Tube ◽  
Pyrex Glass ◽  
Total External Reflection ◽  
Guide Tube ◽  
Long Distance ◽  
X Ray ◽  
Small Crystal ◽  
Simple Consideration ◽  
Pyrex Glass Tube

For diffraction experiments with an extremely small crystal or with very long distance from X-ray source to detecting instrument, the use of an `X-ray guide tube' (XGT) is proposed on the basis of a simple consideration and experiment with a Pyrex-glass tube. X-ray intensities through an XGT of glass and also through a pin hole were measured as a function of photon energy and compared to derive the gain by use of XGT. At wavelengths between Cu Kα and Mo Kα radiations, the observed gain in brightness is about thirty to twenty for the present setup, corresponding to about 50 to 80% of the maximum possible gain calculated on the assumption that the reflectivity of X-ray total external reflection is 1.0.

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