Simple glass-capillary converters of soft x rays

1995 ◽  
Vol 25 (7) ◽  
pp. 700-705 ◽  
Author(s):  
V L Kantsyrev ◽  
A P Inozemtsev ◽  
O V Komardin ◽  
T I Korotkova ◽  
A S Shlyaptseva
Keyword(s):  
X Rays ◽  
Glass Capillary

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.

Some Interesting Work on Capillary Glass Detectors

2014 ◽  
pp. 103-113
Keyword(s):  
Gamma Ray ◽  
X Rays ◽  
Glass Capillary ◽  
Large Area ◽  
Vacuum Technology ◽  
Gas Atmosphere ◽  
Gamma Ray Imaging ◽  
Position Sensitive ◽  
Primary Electrons ◽  
Glass Detectors

In this chapter, the progress of the development of glass capillary plates is described. In some applications, capillary plates have advantages over GEM or other gaseous detectors. For example, they are compatible with vacuum technology allowing them to be used in sealed gaseous detectors. Prototypes of capillary plates combined with photocathodes sensitive to ultraviolet and visible light were the first to be developed and successfully tested. These detectors resemble vacuum imaging microchannel plates, widely used in many applications. However, the glass capillary plates operate in gas atmosphere and in avalanche mode. This offers a possibility to build large area position-sensitive photomultipliers since at atmospheric pressure there are no serious mechanical constrains on the window. Since glass has a high density, the capillary plate can also be used as efficient convertors of X-rays, and be used at the same time as a multiplication structure for the created primary electrons. Such a device is attractive for X-ray and gamma ray imaging and the first successful tests of a prototype of such a detector are described.

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.

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.

Strain Measurements and Laue Diffraction with Microbeams

1994 ◽  
Vol 375 ◽  
Author(s):  
P.-C. Wang ◽  
G. S. Cargill ◽  
I. C. Noyan
Keyword(s):  
X Rays ◽  
Si Substrate ◽  
Glass Capillary ◽  
Laue Diffraction ◽  
Strain Measurements ◽  
X Ray ◽  
Spatially Resolved ◽  
Cu Film ◽  
Ccd Detector ◽  
Single Grain

AbstractWe describe a system being developed to use x-rays for spatially resolved measurements of strain, microstructure and composition in thin films. These capabilities are particularly important for improved understanding of electromigration, stress relaxation, and associated reliability issues in microelectronics. The system uses white radiation collimated and focused with a tapered glass capillary, an area CCD detector for measuring Laue patterns, and an energy sensitive Si detector for measuring lattice spacings. Examples are shown of strain measurements for a 4 μm thick Al film on a Si substrate with 300 μm and 30 μm x-ray beams; of Laue diffraction from a single grain for a 40 μm thick Al foil with a 0.3 μm x-ray beam; and of x-ray fluorescence mapping for a patterned Cu film with a 30 μm x-ray beam.

Polycapillary X-ray optics for microdiffraction

1999 ◽  
Vol 32 (2) ◽  
pp. 160-167 ◽  
Author(s):  
C. A. MacDonald ◽  
S. M. Owens ◽  
W. M. Gibson
Keyword(s):  
Line Emission ◽  
High Energy ◽  
Small Sample ◽  
Quality Data ◽  
Characteristic Line ◽  
X Rays ◽  
Glass Capillary ◽  
Data Set ◽  
Ray Optics ◽  
X Ray

Polycapillary optics,i.e.shaped arrays consisting of hundreds of thousands of hollow glass capillary tubes, can be used to redirect, collimate or focus X-ray beams. X-rays emitted over a large angular range from conventional laboratory-based sources can be transformed into a beam with a small angular divergence or focused onto a small sample or sample area. Convergent beams of X-rays, with convergence angles as high as 15°, have been produced using polycapillary X-ray optics. Focused-spot sizes as small as 20 µm have been achieved, with flux densities two orders of magnitude larger than that produced by pinhole collimation. This results in a comparable decrease in data collection times because of the increase in direct-beam intensity and reciprocal-space coverage. In addition, the optics can be employed to reduce background and provide more convenient alignment geometries. The inverse dependence of the critical angle for total external reflection on photon energy results in suppression of high-energy photons. This effect can be employed to allow the use of higher tube potentials to increase the characteristic line emission and has also been employed to increase significantly theKα/Kβ ratio in Cu radiation. Measurements of X-ray diffraction data and crystallographic analyses have been performed for systems ranging from elemental crystals to proteins. Data from a lysozyme protein `standard' with a slightly convergent beam, taken in 3 min per frame with 2° oscillation with a 2.8 kW source, refined to an intensity variance of 5% compared to a standard data set. High-quality data were also obtained with a 0.03 kW fixed-anode source and a 2° convergent lens in 5 min per frame.

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.

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