• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1297-1303
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• 2021

Most thickness measurement techniques using X-ray radiation are unsuitable in field processes involving fast-moving organic films. Herein, we propose a Compton scattering X-ray radiation method, which probes the light elements in organic materials, and a new simple, non-destructive, and non-contact calibration-free real-time film thickness measurement technique by setting up a bench-top X-ray thickness measurement system simulating a field process dealing with thin flexible organic films. The use of X-ray fluorescence and Compton scattering X-ray radiation reflectance signals from films in close contact with a roller produced accurate thickness measurements. In a high-thickness range, the contribution of X-ray fluorescence is negligible, whereas that of Compton scattering is negligible in a low-thickness range. X-ray fluorescence and Compton scattering show good correlations with the organic film thickness (R² = 0.997 and 0.999 for X-ray fluorescence and Compton scattering, respectively, in the thickness range 0-0.5 mm). Although the sensitivity of X-ray fluorescence is approximately 4.6 times higher than that of Compton scattering, Compton scattering signals are useful for thick films (e.g., thicker than ca. 1-5 mm under our present experiment conditions). Thus, successful calibration-free thickness monitoring is possible for fast-moving films, as demonstrated in our experiments.

• Journal of radiological science and technology
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• v.20 no.2
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• pp.28-33
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• 1997

For the Evaluation of X-ray image intensifier, we measured radiation dose at input of I. I., brightness and fluorescence at output of I. I. by using X-ray exposure meter, optometer and fluorescence meter for the relative conversion factor. Especially, by using fluorescence meter, we could easily get relative conversion factor without having regulated machine by JIS. Since using, the quality of image intensifier is going down. Consequently, it needs continuous quality maintenance.

• Journal of radiological science and technology
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• v.18 no.1
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• pp.71-75
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• 1995

In order to establish the photographic effects and sensitivity of various screens, fluorescence meter is used with convenience. When the radiation quality has been fixed the fluorescence has increased in proportion to X-ray dose. However, the response of fluorescence meter has the dependency of X-ray quality in accordance with KVP. as well as the difference of screen and scatter fraction can influence on the response of fluorescence meter. Using accurate fluorescence meter as a radiation detecter and as for a proper supervision the sensitive materials, we have to aware of the meter's dependency of X-ray quality and the scatter fraction.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.773-780
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• 2003

The characteristics of soft clays is very important for the land development plan. This study is to investigate correlations between the engineering properties and the characteristics of clay minerals of the disturbed clay samples obtained from Sihwa area. This study included X-Ray Diffraction Analysis, X-Ray Fluorescence Spectrometer Analysis, Scanning Electron Microscopy Analysis and Energy Dispersive X-Ray Spectrometer Analysis. The correlations between the clay mineral properties and the laboratory and field testing results were investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2298-2304
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• 2012

X-ray fluorescence spectrum analysis method can be applied in many areas, including concentration analysis of RoHS elements and heavy metals etc. and we can get analysis results in a relatively short time. Because X-ray fluorescence spectrum has noises and several artifacts that lowers the accuracy of the analysis. This paper analyzes the characteristics of the noise of the X-ray fluorescence spectrum to increase the accuracy of analysis. X-ray fluorescence spectrum have the characteristics of shot noise (Poisson noise), so the noise size is relatively large in the small signal portion and the noise the size is relatively small in the large part of the signal. Existing methods of analysis and to remove noises is a method for general purposes algorithm. Since these algorithm does not reflect these noise characteristics, we get distorted analysis result. We can design efficient noise remove algorithm based on the accurate noise analysis method, and we expect high accuracy results of the elemental concentration analysis result.

• Journal of the Korean Vacuum Society
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• v.17 no.3
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• pp.247-252
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• 2008

By using the transmission anode x-ray tube developed to apply to the hand-held XRF equipment, we carried out XRF experiment and evaluated the influences of the x-ray tube on XRF spectra. XRF data, which is measured using the W-target and Rh-target tube, were good agreements with the known results. FWHM of Fe $K_{\alpha}$-line measured by W-target tube with the 35 kV-tube voltage and the $40{\mu}A$-tube current was 180 eV. This result reveals that our XRF equipment using the transmission anode x-ray tube is enough for a qualitative analysis of materials. By comparison XRF data with the integrated intensity of x-ray tube, it was confirmed that Rh-target tube is better than W-target tube for application to the hand-held XRF equipment.

• Journal of the Korean Vacuum Society
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• v.17 no.3
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• pp.234-239
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• 2008

Tungsten and rhodium target tube for a 40 kV x-ray transmission anode was developed to apply to the hand-held XRF(X-Ray Fluorescence) apparatus and its characteristics were evaluated. From the measurement of the energy distribution and dose of x-ray, it was confirmed that our results were good agreements with the known ones. The optimum thickness of metal film deposited on Be window to extract the maximum dose were $2.6{\mu}m$ and $2.7{\mu}m$ in case of W-target tube and Rh-target tube, respectively. When it was continuously worked during 30 min. at 40 kV in tube voltage and at $60{\mu}A$ in tube current, the temperature at target did not exceed $50^{\circ}C$. Our results reveals that the 40 kV x-ray transmission anode tube can be applied to the hand-held XRF apparatus.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.107-114
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• 2023

X-ray fluorescence analysis has been widely used in the field of science and industry because it gives information about elements and their concentrations without destruction of samples. To increase analysis accuracy of fluorescence generated by photons of the transmission-type X-ray tube for mixture and compound samples would be recommend to have strong energy near 10 keV and 20 keV simultaneously. Tungsten of 9.65 keV and molybdenum of 17.48 keV were considered as targets with dual deposition structure for obtaining two strong characteristic X-rays, and the transmission-type X-ray tube was analyzed using Geant4 Monte Carlo simulation. The W-Mo structure resulted in strong characteristic X-ray near 10 keV and 20 keV simultaneously. A structure with Mo-W multilayers of 5 ㎛ thick also gave optimal spectrum. Various material combination and thickness optimization for the dual-structured target can give X-ray spectrum with strong characteristic X-ray of specific energies.

• Journal of Radiation Protection and Research
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• v.10 no.1
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• pp.14-28
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• 1985

The development of mono energetic photon sources using $K_{\alpha}$ fluorescence X-ray of pure material was carried out in the energy range below 100 keV. The monoenergetic photons are very useful in the calibration of the radiation measuring instruments and can be produced as the $K_{\alpha}$ fluorescence X-ray by irradiating the bremsstrahlung to the thin pure metal foils called ‘radiators’. In this experiment, several radiators such as $_{47}Ag,\;_{50}Sn,\;_{68}Er,\;_{70}Yb,\;and\;_{82}Pb$ provide the wide monoenergetic photon energy ranging from 20 keV to 80 keV. By the spectrometry with HpGe LEPS, spectral purity factors which measure the monochrometicity for the $K_{\alpha}$ fluorescence X-ray, were determined as $0.64{\sim}0.94$. Dosimetry for the purpose of the determination of the exposure rate with a 600cc thin window ionization chamber, which was calibrated by the standard free-air ionization chamber, was performed. Exposure rates ranging $8.3{\sim}232.5mR/h$ was obtained according to the $K_{\alpha}$ fluorescence X-ray energy for each radiator.

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.861-866
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• 1993

In general, the concentration of constituents can be more accurately measured in x-ray fluorescence analysis of Fe-Ni-Cr alloy by reducing and correcting the matrix effect with standard ingot samples. Because of the difficult the treatment at a high temperature in preparing the ingot samples of various concentrations, several standard specimens were prepared by mixing the powders of the metallic oxides in certain proportions and pressing them with a costant pressure. With the metallic oxide specimens thus obtained, different matrix coefficients were calculate from the intensities of the strength of the x-ray fluorescence and the concentration of the substances. It is found that effects of Fe and Cr on Ni are absorption rich and effects of Fe and Ni on Cr are enhancement rich, whereas Ni enhances Fe Fluorescence but Cr absorves Fe K${\alpha}$ line. And the x-ray fluorescence intensities were compared and analyzed between the metallic oxides and the ingot samples.