System for Non-Dispersive Analysis of Lunar X-Rays from Apollo

1969 ◽  
Vol 13 ◽  
pp. 330-341
Author(s):  
P. Gorenstein ◽  
H. Gursky ◽  
I. Adler ◽  
J. Trombka
Keyword(s):  
Chemical Composition ◽  
Lunar Surface ◽  
Regional Differences ◽  
Detection System ◽  
X Rays ◽  
X Ray ◽  
Service Module ◽  
Dispersive Analysis ◽  
Theoretical Performance

A non-dispersive X-ray detection system consisting of proporticnal counters plus filters is being prepared for the Command-Service Module of the Apollo spacecraft as part of a “geochemistry“ package. It will detect solar induced characteristic X-rays from the abundant elements on the lunar surface during the orbiting phases of the mission. The objective will be a compilation of a map of the lunar chemical composition and to detect regional differences. The system and its theoretical performance are described.

Measurement of Mass Absorption Coefficients Using Compton-Scattered Cu Radiation in X-ray Diffraction Analysis

1990 ◽  
Vol 34 ◽  
pp. 325-335 ◽  
Author(s):  
Steve J. Chipera ◽  
David L. Bish
Keyword(s):  
Chemical Composition ◽  
Solid State ◽  
Absorption Coefficient ◽  
Mass Absorption Coefficient ◽  
X Rays ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
Solid State Detector ◽  
X Ray ◽  
Mass Absorption

AbstractThe mass absorption coefficient is a useful parameter for quantitative characterization of materials. If the chemical composition of a sample is known, the mass absorption coefficient can be calculated directly. However, the mass absorption coefficient must be determined empirically if the chemical composition is unknown. Traditional methods for determining the mass absorption coefficient involve measuring the transmission of monochromatic X-rays through a sample of known thickness and density. Reynolds (1963,1967), however, proposed a method for determining the mass absorption coefficient by measuring the Compton or inelastic X-ray scattering from a sample using Mo radiation on an X-ray fluorescence spectrometer (XRF). With the recent advances in solid-state detectors/electronics for use with conventional powder diffractometers, it is now possible to readily determine mass absorption coefficients during routine X-ray diffraction (XRD) analyses.Using Cu Kα radiation and Reynolds’ method on a Siemens D-500 diffractometer fitted with a Kevex Si(Li) solid-state detector, we have measured the mass absorption coefficients of a suite of minerals and pure chemical compounds ranging in μ/ρ from graphite to Fe-metal (μ/ρ = 4.6-308 using Cu Kα radiation) to ±4.0% (lσ). The relationship between the known mass absorption coefficient and the inverse count rate is linear with a correlation coefficient of 0.997. Using mass absorption coefficients, phase abundances can be determined during quantitative XRD analysis without requiring the use of an internal standard, even when an amorphous component is present.

Microanalytical studies (X-ray photoelectron spectrometry) of surface hydration reactions of cement compounds

1983 ◽  
Vol 310 (1511) ◽  
pp. 85-92 ◽  
Keyword(s):  
Blast Furnace ◽  
Chemical Composition ◽  
Kinetic Energy ◽  
Blast Furnace Slag ◽  
X Rays ◽  
Hydration Time ◽  
X Ray ◽  
Tentative Interpretation ◽  
Furnace Slag ◽  
Cement Compounds

X-ray photoelectron spectrometry (X.p.s.) measures the kinetic energy of electrons photoejected from a solid surface by soft X-rays. The kinetic energy of the photoelectrons can be related to the binding energy that these electrons had originally in the solid. X.p.s. is a rather new technique for studying cements. It has been used recently in the surface analysis of C 3 S, C 2 S, C 3 A and blast-furnace slag grains during their hydration. Changes in chemical composition have been found as soon as the surface comes into contact with water, shown by a change in the shape, position an intensity of characteristic peaks like Ca 2p , Si 2p , O l8 and a reduction of characteristic ratios Ca/Si or Al/Si. A tentative interpretation of X.p.s. kinetic curves as a function of hydration time is presented.

scholarly journals Corrosion Resistance of Inconel 625 CMT-Cladded Layers after Long-Term Exposure to Biomass and Waste Ashes in High-Temperature Conversion Processes

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4374
Author(s):  
Aleksandra Błoniarz ◽  
Marcus Schreiner ◽  
Markus Reinmöller ◽  
Agnieszka Kopia
Keyword(s):  
Chemical Composition ◽  
Inconel 625 ◽  
X Rays ◽  
X Ray Diffraction ◽  
Cold Metal Transfer ◽  
X Ray ◽  
Xrf Scanning ◽  
Corrosion Mechanisms ◽  
Cold Metal

The present study investigated the effect of corrosion on an Inconel 625-cladded layer using the cold metal transfer (CMT) method. The corrosion was caused by various ashes and high process temperatures. The ashes were obtained from the biomasses of mixed wood and oat straw, as well as from sewage sludge, by ashing. Long-term corrosion tests were carried out at 650 °C over a period of 1000 h. The chemical composition, mineral phases, and corrosion effects were studied by X-ray fluorescence (XRF), scanning electron microscopy equipped with energy-dispersive X-rays (SEM–EDX), and X-ray diffraction (XRD) from the surface and on the cross-section of the samples. The chemical composition of the ashes was quite different, but representative of their particular fuel. Together with the effects of the operating temperature and mass transfer, significant differences in the degree of the corrosion depth were detected for the various ashes. For the investigated samples, the corrosion mechanisms were inferred based on the identified corrosion products.

scholarly journals An Automatic Stabilized Detection System for Measuring Soft Celestial X-Rays

1971 ◽  
Vol 41 ◽  
pp. 211-212
Author(s):  
A. J. F. Den Boggende ◽  
H. F. Van Beek ◽  
A. C. Brinkman ◽  
H. Th. J. A. Lafleur
Keyword(s):  
Normal Mode ◽  
Spectral Distribution ◽  
Detection System ◽  
X Rays ◽  
X Ray

In order to observe celestial X-ray sources an instrument is under development to be launched in the Astronomical Netherlands Satellite (ANS) in 1974. The aim of the experiment is to measure the spectral distribution of the sources. If there is some evidence that a source should be a pulsar the instrument can be switched from the normal mode to the pulsar mode. In this latter mode the detected photons are labeled in time using an on board clock. The ANS will have a pointing mode and a slow scanning mode. The maximum observing time per orbit for one object will be about 2000 s.

High-resolution fast-tomography brain-imaging beamline at the Taiwan Photon Source

2021 ◽  
Vol 28 (5) ◽  
Author(s):  
Hsiang Hsin Chen ◽  
Shun-Min Yang ◽  
Kai-En Yang ◽  
Ching-Yu Chiu ◽  
Chia-Ju Chang ◽  
...  
Keyword(s):  
Brain Imaging ◽  
Brain Mapping ◽  
3D Imaging ◽  
Detection System ◽  
High Energy ◽  
Large Animal ◽  
X Rays ◽  
X Ray ◽  
Photon Source ◽  
Very High

The new Brain Imaging Beamline (BIB) of the Taiwan Photon Source (TPS) has been commissioned and opened to users. The BIB and in particular its endstation are designed to take advantage of bright unmonochromatized synchrotron X-rays and target fast 3D imaging, ∼1 ms exposure time plus very high ∼0.3 µm spatial resolution. A critical step in achieving the planned performances was the solution to the X-ray induced damaging problems of the detection system. High-energy photons were identified as their principal cause and were solved by combining tailored filters/attenuators and a high-energy cut-off mirror. This enabled the tomography acquisition throughput to reach >1 mm3 min−1, a critical performance for large-animal brain mapping and a vital mission of the beamline.

scholarly journals Investigating the interstellar dust through the Fe K-edge

2017 ◽  
Vol 609 ◽  
pp. A22 ◽  
Author(s):  
D. Rogantini ◽  
E. Costantini ◽  
S. T. Zeegers ◽  
C. P. de Vries ◽  
W. Bras ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Interstellar Dust ◽  
Effective Area ◽  
European Synchrotron Radiation Facility ◽  
Galactic Centre ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
The Individual

Context. The chemical and physical properties of interstellar dust in the densest regions of the Galaxy are still not well understood. X-rays provide a powerful probe since they can penetrate gas and dust over a wide range of column densities (up to 1024 cm-2). The interaction (scattering and absorption) with the medium imprints spectral signatures that reflect the individual atoms which constitute the gas, molecule, or solid. Aims. In this work we investigate the ability of high resolution X-ray spectroscopy to probe the properties of cosmic grains containing iron. Although iron is heavily depleted into interstellar dust, the nature of the Fe-bearing grains is still largely uncertain. Methods. In our analysis we use iron K-edge synchrotron data of minerals likely present in the ISM dust taken at the European Synchrotron Radiation Facility. We explore the prospects of determining the chemical composition and the size of astrophysical dust in the Galactic centre and in molecular clouds with future X-ray missions. The energy resolution and the effective area of the present X-ray telescopes are not sufficient to detect and study the Fe K-edge, even for bright X-ray sources. Results. From the analysis of the extinction cross sections of our dust models implemented in the spectral fitting program SPEX, the Fe K-edge is promising for investigating both the chemistry and the size distribution of the interstellar dust. We find that the chemical composition regulates the X-ray absorption fine structures in the post edge region, whereas the scattering feature in the pre-edge is sensitive to the mean grain size. Finally, we note that the Fe K-edge is insensitive to other dust properties, such as the porosity and the geometry of the dust.

Coherent and incoherent scattering of low-energy X-ray photons in the atomic region 13 ≤ Z ≤ 82

1996 ◽  
Vol 74 (1-2) ◽  
pp. 10-16 ◽  
Author(s):  
D. V. Rao ◽  
R. Cesareo ◽  
G. E. Gigante ◽  
D. V. Rao ◽  
G. E. Gigante
Keyword(s):  
Cross Sections ◽  
Detection System ◽  
Form Factors ◽  
Coherent Scattering ◽  
Incoherent Scattering ◽  
X Rays ◽  
Bremsstrahlung Radiation ◽  
X Ray ◽  
Scattering Cross ◽  
Scattering Cross Sections

Coherent- and incoherent-scattering cross sections for the elements Al, Cu, Y, In, Au, and Pb were measured using nearly monoenergetic unpolarized 35.86 and 39.96 keV X-ray beams with high-resolution Si (Li) detectors. Bremsstrahlung radiation from an X-ray tube was used to excite nearly monoenergetic X-rays in secondary targets. To improve the efficiency of the detection system the excitation source, detector, and the target assembly were placed in a vacuum chamber and a pressure of 10−2 mbar was maintained throughout the measurements. This system considerably reduced the background and scattering effects and improved the monochromacy. Experimental coherent-scattering cross sections are compared with the normalized integrated coherent-scattering cross sections calculated using the relativistic, nonrelativistic, and relativistic-modified form factors. Experimental incoherent-scattering cross sections are compared with the theoretical values, calculated using the nonrelativistic incoherent-scattering function. Good correspondence is observed between experimental and theoretical values in the given energy region.

scholarly journals Development and Validation of an X-ray Imaging Detector for Digital Radiography at Low Resolution

2020 ◽  
Vol 7 (2) ◽  
pp. 181-187
Author(s):  
Abdiel Ramírez Reyes ◽  
Gerardo Herrera Corral ◽  
Elsa Ordoñez Casanova ◽  
Héctor Alejandro Trejo Mandujano ◽  
Uzziel Caldiño Herrera
Keyword(s):  
Detection System ◽  
X Rays ◽  
Modulation Transfer ◽  
Resolution Limit ◽  
Large Area ◽  
X Ray ◽  
Regular Type ◽  
Digital Radiographs ◽  
Ccd Sensor ◽  
X Ray Imaging

Digital X-ray detectors are required in different sciences and applications, however many high quality devices are expensive although high-resolution images are not always required. We present an easy way to build a detector capable of forming X-ray digital images and video with a very large area (18×18 cm2). The detector is formed by three main components: scintillator, optics lenses and CCD sensor. Basically, the device converts the X-rays into visible light which is then collected by the CCD sensor. The scintillator is Gadox type, from Carestream®, 18×18 cm2, regular type, lambda 547 nm. The optics lenses are generic, with manual focus and widely visual field. The CCD sensor has a size of 1/3″, 752 × 582 pixels, monochrome, 20 FPS, 12 bits ADC and pixel size of 3.8 μm. With the built detector and an X-ray source, we formed an X-ray imaging detection system to generate digital radiographs of biological or inert objects-examples are given-, as well as real-time X-ray video. Additionally, the spatial resolution limit was measured in terms of Modulation Transfer Function by the method of opaque edge from a lead sheet with a result of 1.1 Lp/mm. Finally using a filter, the focal spot of the X-ray source is measured, resulting in a diameter of 0.9 mm (FWHM).

Investigation Of Geometrical Effects in X-Ray Microfluorescence Analysis of Geological Samples

1993 ◽  
Vol 37 ◽  
pp. 685-688
Author(s):  
Marek Lankosz ◽  
Peter A. Pella
Keyword(s):  
Chemical Composition ◽  
Edge Effects ◽  
Mineral Inclusion ◽  
X Rays ◽  
Geological Samples ◽  
X Ray ◽  
Mathematical Expressions ◽  
Geometrical Effects

AbstractGeometrical effects occur when primary x-rays irradiate a mineral inclusion which lies close to the boundary between it and a surrounding mineral having a different chemical composition. An investigation of one of these near-edge effects was performed in the case when x-ray microfluorescence is applied for analysis. Analytical mathematical expressions were developed to correct for this effect and were tested exper imentally.

scholarly journals An Audit of Computer Aided Fracture Detection System

2019 ◽  
Vol 9 (2) ◽  
pp. 868-872
Keyword(s):  
Medical Imaging ◽  
Detection System ◽  
Correct Diagnosis ◽  
Region Of Interest ◽  
Automatic Identification ◽  
X Rays ◽  
Fracture Detection ◽  
X Ray ◽  
Course Of Action ◽  
Computer Aided

X-Ray images are the most widely recognized methods for medical imaging accessibility for individuals during the wounds and mishaps. X-rays are most frequent and the oldest form of medical imaging. Yet, the minute fracture identification using the X-Ray image is beyond the realm of imagination,because of the complication of bone organisation and the dissimilarity in visual attributes of fracture upon their location. This is the reason why it it is hard to detect the fractures and furthermore decide the seriousness of the damage. The major challenges of X-Ray imaging are the presence of noise, intensity ambiguity, and overlapping tissues. This creates a hurdle in correct diagnosis and delays treatment. The various rates require the human services experts to analyze countless x-ray images. computerized detection of fractures in X-Ray images can be a huge commitment for helping the doctors in settling on quicker and increasingly precise diagnostic decisions and speeds up the plan for the treatment. This research compares the existing fracture detection techniques.From various fractures, programmed identification is viewed as challenging since they are unique and variable in presentation and their results are quite un predictable.The major challenges for computer-aided fracture detection can be accurate segmentation process, automatic identification of the region of interest (bone fracture), evaluation and suggestive course of action.

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