scholarly journals Экспериментальная и теоретическая оценка рентгеноконтрастности тонкомерных образцов никелида титана с микронными покрытиями на основе Ti и Ta

2020 ◽  
Vol 90 (4) ◽  
pp. 671
Author(s):  
Е.Ю. Гудимова ◽  
Л.Л. Мейснер ◽  
С.Н. Мейснер ◽  
О.И. Шабалина ◽  
А.А. Бощенко ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Endoscopic Surgery ◽  
Small Diameter ◽  
Comparative Data ◽  
Mass Absorption Coefficient ◽  
Tini Alloy ◽  
X Rays ◽  
Ray Method ◽  
Alloy Wire ◽  
X Ray

The prospect of applying of Ti-Ta coatings of micron thickness in order to increase the X-ray visibility of the small-diameter TiNi samples for endoscopic surgery is analyzed in the paper. The radiopaque properties of the Ta and Ti-Ta coatings with thickness of 1-2 μm on the surfaces of the TiNi alloy wire a diameter of 152 μm were investigated. Comparative data of calculated (according to the X-rays mass absorption coefficient) and experimental (with use of X-ray method on the angiographic installation) characteristics of the X-ray visibility of coated samples are given. It is shown that the Ti60-70Ta40-30 coatings with a thickness of 1–2 μm lead to an increase in twice the X-ray visibility of the coated TiNi wire. The change in the X-ray visibility of coated TiNi samples (wire and semi-stents) depending on the concentration of tantalum in the coating was analyzed with use of different X-ray angiographic modes.

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.

scholarly journals Synthesis and Characterisation of Thin Films of Bismuth Triiodide for Semiconductor Radiation Detectors

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Alka Garg ◽  
Monika Tomar ◽  
Vinay Gupta
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Room Temperature ◽  
Active Material ◽  
Visible Region ◽  
Radiation Detectors ◽  
Radiation Absorption ◽  
X Rays ◽  
X Ray ◽  
Bismuth Iodide

Bismuth iodide is a potentially active material for room temperature radiation detector, as it is well reported in the literature that it has both wide energy band gap and high atomic absorption coefficient. Crystalline films of high atomic number and high radiation absorption coefficient can absorb the X-rays and convert them directly into electrical charges which can be read by imaging devices. Therefore, it was proposed to grow thin films of Bismuth iodide on glass substrate using thermal evaporation technique in vacuum to avoid the inclusion of impurities in the films. The structural studies of the films were carried out using XRD and optical absorption measurement was carried out in the UV/VIS region using spectrophotometer. All Bismuth iodide films grown at room temperature are polycrystalline and show X-ray diffraction peaks at angles reported in research papers. The optical transmission spectra of BiI3 films show a high transmission of about 80% in visible region with a sharp fall near the fundamental absorption at 650 nm. Resistivity of the as-grown film was found to be around 1012 ohm-cm suitable value for X-ray detection application. Films were subjected to scanning electron microscopy to study the growth features of both as-grown and annealed films.

Quantitative Determination of Carbon in Solid Hydrocarbons Using the Intensity Ratio of Incoherent to Coherent Scattering of X-Rays

1964 ◽  
Vol 18 (6) ◽  
pp. 171-174 ◽  
Author(s):  
C. J. Toussaint ◽  
G. Vos
Keyword(s):  
Intensity Ratio ◽  
Coherent Scattering ◽  
X Rays ◽  
Ray Method ◽  
Sample Weight ◽  
X Ray ◽  
Carbon Determination ◽  
Solid Hydrocarbons ◽  
Good Agreement

A method is presented for the determination of carbon in solid hydrocarbons using the intensity ratio of incoherent to coherent scattering of x-rays. The method is very rapid with precision at the 95% confidence level of about ±0.3%. The minimum sample weight necessary is 0 2 g. Analysis of samples by the x-ray method shows good agreement with values obtained by microcombustion. Finally a general comparison between different methods for carbon determination in solid hydrocarbons is discussed.

Measuring Residual Stress with the Indentation Method in Struc­tural Ceramics

2005 ◽  
Vol 297-300 ◽  
pp. 515-520
Author(s):  
Tarou Tokuda ◽  
Rong Gang Wang ◽  
Mitsuo Kido ◽  
Gonojo Katayama
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Phase Transformation ◽  
Residual Stresses ◽  
Treatment Method ◽  
Indentation Load ◽  
X Rays ◽  
Ray Method ◽  
Indentation Method ◽  
X Ray

This study deals with the indentation method of measuring residual stress in structural ceramics. First we investigate the appropriate pretreatment for measuring fracture toughness (basis value, KC) while avoiding any influence from residual stress, which is important when estimating residual stress using the indentation method. Based on the fracture toughness value, the residual stresses in Al2O3, Si3N4 and ZrO2 ceramics are estimated using the indentation method. Phase transformation is a problem when estimating residual stress using the indentation method with ZrO2 ceramics. Residual stresses in Al2O3 and Si3N4 can be largely eliminated by annealing the specimen after hand grinding. Consequently, it is thought that this treatment method is effective for determining the basis value KC. The estimated residual stress values in Al2O3 and Si3N4 obtained by the indentation method at 98 N corresponded closely to the values obtained wih X-rays. The residual stress value obtained by the indentation method for ZrO2 was close to the value obtained through the X-ray method, when the indentation load was 294 N. When estimating the residual stress in ZrO2 using the indentation method, the influence of the phase transformation caused by the indentation is added onto the original residual stress, when the indentation is small. The influence becomes smaller when the indentation load is large. If the applied indentation load is between 294 N and 490 N, the indentation method is effective for estimating the residual stresses in Al2O3, Si3N4 and ZrO2 ceramics.

Mass Absorption Corrected X-Ray Powder Diffractograms. Part 1: Measuring Pyrite in Powdered Coals

1990 ◽  
Vol 5 (1) ◽  
pp. 44-47 ◽  
Author(s):  
David L. Wertz
Keyword(s):  
Absorption Coefficient ◽  
Limit Of Detection ◽  
Diffraction Peak ◽  
Mass Absorption Coefficient ◽  
Measured Intensity ◽  
X Ray ◽  
Mass Absorption ◽  
Powdered Coal ◽  
Analysis Protocol

AbstractAn X-ray analysis method has been developed for the quantitative analysis of pyrite (FeS2) in coals and lignites. Requiring neither the use of external or internal references, the method linearly relates diffraction peak area in the absorption corrected X-ray diffractogram obtained from the finely powdered coal to the pyrite abundance. The [311] diffraction peak of pyrite (FeS2) has been used to develop the analysis protocol. The Argonne premium coals have been used as the experimental subjects. The abundance of pyrite in each coal has been measured from the absorption corrected diffractograms, which has been constructed from the experimentally measured diffraction intensities and the mass absorption coefficient of each coal sample. The accuracy (accessed from the figure-of-merit and the net count uncertainty associated with the 1.63 Å pyrite peak) as well as the lower limit of detection for pyrite in these coals is presented. The role of the mass absorption coefficient in the conversion of the measured intensity to the absorption corrected intensity is discussed.

scholarly journals A critical-absorption photometer for the study of the Compton effect

1928 ◽  
Vol 119 (783) ◽  
pp. 526-530
Keyword(s):  
Absorption Coefficient ◽  
Wave Length ◽  
Light Element ◽  
Compton Effect ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Length Changes ◽  
Absorption Measurements ◽  
Ray Scattering

That a change of wave-length occurs in X-ray scattering was first indicated by absorption measurements with the ionisation chamber, which showed that the absorption coefficient of a light element like aluminium was slightly greater for the scattered than for the primary X-rays. Later more conclusive and direct evidence was obtained when spectrometric analysis of the scattered X-rays was made first by the ionisation and afterwards by the photographic method. This analysis disclosed the existence of an unshifted as well as the shifted line, and showed also that the latter becomes relatively more prominent with diminishing wave-length and lower atomic number of the scattering element. After the main features of the Compton effect were established by means of spectrometric measurements, however, absorption measurements with the ionisation method have again been employed for a detailed study of the phenomenon, for such measurements are much quicker than the spectrum experiments, where the final energy available is much smaller on account of the double scattering involved. As mentioned above, the absorption measurements were based on the slight increase in the absorption coefficient of a light element when the wave-length changes from the unmodified to the modified value. The much larger and sudden diminution in absorption of X-rays when the frequency is altered from the short to the long wave-length side of the critical K-absorption limit of the element used as a filter, furnishes us with an easy and convenient method of exhibiting the wave-length change in X-ray scattering. In the present paper will be described a photographic wedge photometer based on this principle, which enables the characteristics of the Compton effect to be readily observed. It may be pointed out that the same idea could no doubt be utilised also in connection with the ionisation measurements of the Compton effect.

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