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This study utilizes the monochromatic X-ray radiation device established by the National Institute of Metrology, China, to conduct a systematic experimental investigation of the mass attenuation coefficients of niobium, molybdenum, tantalum, and tungsten metals near their K absorption edges. The device's ability to generate continuously tunable monochromatic X-rays and accurately measure photon counts provides an ideal condition for precise mass attenuation coefficient measurements. This study employs a minimum energy step of 0.1 keV to systematically obtain the jump ratio rK and jump factor JK near the K-absorption edges of the four materials. The experimental measurements are compared with theoretical values from NIST-XCOM, NIST-FFAST, and Phy-x databases, demonstrating a consistent trend between the experimental and theoretical results, with relative deviations within acceptable limits, thereby validating the reliability of the theoretical models. An uncertainty analysis reveals a combined relative uncertainty of less than 2.7 %, indicating that the experimental results and theoretical values are in good agreement, with deviations and uncertainties within acceptable ranges. This research provides important experimental data and theoretical references for the application of monochromatic X-ray radiation devices in the field of mass attenuation coefficient measurements. [ABSTRACT FROM AUTHOR]

The L III subshell photoelectric cross section, jump ratio, jump factor, and Davisson-Kirchner ratio of iridium have been determined by mass attenuation coefficients. The measurements have been performed using the X-ray attenuation method in narrow beam geometry. The obtained results have been compared with the tabulated values of XCOM (Berger et al. XCOM: Photon cross section database (version 1.3). NIST. Available at . 2005) and FFAST (Chantler et al. X-ray form factor, attenuation and scattering tables (version 2.1). NIST. Available at . 2005). [ABSTRACT FROM AUTHOR]

L III jump ratio, jump factor and its related parameters for Pt and Tl have been measured by using photons of energy 59.54 keV from 241 Am source. The measurements are made by using gamma attenuation method in secondary excitation geometry with high resolution (155 eV at 5.9 keV) Si(Li) detector. X-rays energies, above and below the L III edge for the targets of Pt and Tl are obtained by using secondary target of Br, Co, Cu, Fe, Ga, Ni, Pt, Se, Sr, Tl and Zn. The measurements are compared with the theoretical values of total attenuation cross-sections, L III Jump ratio, jump factor; Davisson–Krichner ratio and L III sub-shell oscillator strength obtained by using mass attenuation coefficients from WinXCom. It is observed that the measured values are in good agreement with theoretical results. These measurement shall enhances the understanding of material characteristics of Pt and Tl, as these are widely used in biological, chemical, medical, electronics and petroleum industry. [ABSTRACT FROM AUTHOR]

The total attenuation cross section at the K edge, absorption jump ratio, jump factor, Davisson-Kirchner ratio, and oscillator strength parameters for the K shell were determined by measuring the total attenuation cross sections around the K edge for Pr, Nd2O3, and Sm. The measurements were performed in a secondary excitation geometry using the Kα2, Kα1, Kβ1, and Kβ2 X-rays (in the region from 31.817 to 55.293 keV) from different secondary source targets excited by the 59.54 keV γ-photons from an 241Am annular source. It is the first time that the Davisson-Kirchner ratio values have been determined for present samples. The experimental results were compared with the theoretically calculated and other available experimental results. [ABSTRACT FROM AUTHOR]

The K shell absorption jump factors and jump ratios for La 2 O 3 , Ce and Gd samples have been determined using the gamma or X-ray attenuation and EDXRF methods. It is the first time that the K shell absorption jump factor and jump ratio have been discussed for present elements using two different methods. To detect K X-rays, a high resolution Si(Li) detector was used. The experimental results of K shell absorption jump factors and jump ratios were compared with the theoretically calculated ones. [ABSTRACT FROM AUTHOR]

Abstract: Energy dispersive X-ray fluorescence technique (EDXRF) has been employed for measuring L3-subshell absorption jump ratios, and jump factors, for high Z elements. Jump factors and jump ratios for these elements have been determined by measuring L3 subshell fluorescence parameters such as L3 subshell X-ray production cross section , L3 subshell fluorescence yield, , total L3 subshell and higher subshells photoionization cross section . Measurements were performed using a Cd-109 radioactive point source and an Si(Li) detector in direct excitation experimental geometry. Measured values for jump factors and jump ratios have been compared with theoretically calculated and other experimental values. [Copyright &y& Elsevier]

Abstract: The LIII subshell absorption jump ratio and jump factor of wolfram have been measured by two different methods. In the first method the mass attenuation coefficients have been obtained by narrow beam transmission geometry to calculate the LIII subshell absorption jump ratio and jump factor. In the latter these parameters have been derived from the LIII subshell X-ray production and the photoionization cross sections of the LIII subshell and higher subshells determined by Energy Dispersive X-ray Fluorescence technique and narrow beam transmission geometry, respectively. The results obtained by both methods have been compared with theoretical and experimental values. They are in good agreement with each other. [Copyright &y& Elsevier]

Abstract: 59.5keV gamma rays scattered by an aluminum foil have been used as a radiation source to measure the absorption jump factor and jump ratios for absorbers Ce, Pr, Nd, Sm, Eu and Tb. The theoretical and experimental values are compared with the corresponding ones in the literature. [Copyright &y& Elsevier]

Abstract: The L III subshell absorption jump ratio and jump factor of tantalum have been calculated for the first time by the mass attenuation coefficients determined using narrow transmission geometry, primary source (241Am annular radioisotope source) and secondary source targets (Ni, Cu, Zn, Ga, As, Tb, Ho, Er, Tm, Yb, Cu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi). The obtained results have been compared with theoretical values. They are in good agreement with each other. [Copyright &y& Elsevier]

Abstract: This article presents experimental values of the K-shell jump factor and jump ratio (ratio of the K-shell photoionization cross section to the photoionization cross section of the rest of the atom at the K edge) for some elements in 76≤Z≤92 using an energy dispersive X-ray fluorescence (EDXRF) spectrometer and compares those values with the theoretical ones giving reasonable agreement. The experimental values have been determined using the fluorescence parameters: K α production cross sections, K β /K α X-rays intensity ratios, total atomic attenuation cross sections, etc. To the best of our knowledge, K-shell jump ratios and jump factors have been measured without having any data on K edge for the first time in these elements. The results have been plotted versus atomic number. [Copyright &y& Elsevier]

Abstract: Some photonic energy absorption parameters such as the mass attenuation coefficient μ t , the molecular σ M , atomic σ A , the electronic cross-sections σ E , the effective atomic number Z eff and the electron density N E have been calculated and measured. We have gained the terms jump factor of effective atomic number JZ eff and jump factor of electronic density JN E to literature with the help of these fundamental parameters. Also, we want to obtain both XAFS effect and the applicability of mixture rule. The most interesting finding in this study is that the trend of the total molecular, atomic and electronic cross-sections is getting beyond the measure by the absorption edge and these cross-sections are affected in the region of absorption edge. The obtained results have been compared with some other theoretical values given earlier. [ABSTRACT FROM AUTHOR]

Abstract: In order to determine the effect of XAFS (X-ray absorption fine structure) on J zeff , we have measured μ/ρ values of compounds, which are determined by the mixture rule or the independent atomic model. Also, we want to obtain both XAFS effect and non-applicability or applicability of mixture rule. The most crucial finding in this study is that measurement of the effective atomic number is not appropriate near the absorption edge and the effective atomic number is affected by near the absorption edge. The results obtained have been compared with theoretical values. Also, the objective of this study is to show that there is a term “J zeff ” between effective atomic numbers and absorption jump factor. [ABSTRACT FROM AUTHOR]

Abstract: In order to measure atomic, molecular and electronic cross-section; the effective atomic number, density of electron and absorption jump factor, we have first measured μt values of compounds which are determined by mixture rule using transmission method. In order to measure experimentally the effective atomic number within absorption jump factors of compounds with Ce, the X-ray source used Am-241 whose gamma rays were stopped at secondary source (Sm), thus producing Kα and Kβ X-ray emission. The most crucial finding in this study is that measurement of the effective atomic number is not appropriate near to the absorption edge and the effective atomic number is affected by near to the absorption edge. The results obtained have been compared with theoretical values. [Copyright &y& Elsevier]

Abstract: The K shell absorption jump factors and jump ratios have been measured in the elements between Tm (Z =69) and Os(Z =76) without having any mass attenuation coefficient at the upper and lower energy branch of the K absorption edge. The jump factors and jump ratios for these elements have been determined by measuring K shell fluorescence parameters such as the total atomic absorption cross-sections, the Kα X-ray production cross-sections, the intensity ratio of the Kβ and Kα X-rays and the K shell fluorescence yields. We have performed the measurements for the calculations of these values in attenuation and direct excitation experimental geometry. The K X-ray photons are excited in the target using 123.6keV gamma-rays from a strong 57Co source, and detected with an Ultra-LEGe solid state detector with a resolution 0.15keV at 5.9keV. The measured values have been compared with theoretical and others’ experimental values. The results have been plotted versus atomic number. [Copyright &y& Elsevier]

Abstract: The K-shell absorption jump factors and jump ratios were derived from new mass attenuation coefficients measured using an energy dispersive X-ray fluorescence (EDXRF) spectrometer for Tm, Yb elements being Tm2O3, Yb2O3 compounds and pure Lu, Hf, Ta, W, Re and Os. The measurements, in the region 56–77keV, were done in a transmission geometry utilizing the K α1, K α2, K β1 and K β2 X- rays from different secondary source targets (Yb, Ta, Os, W, Re and Ir, etc.) excited by the 123.6keV γ-photons from an 57Co annular source and detected by an Ultra-LEGe solid state detector with a resolution of 150eV at 5.9keV. Experimental results have been compared with theoretically calculated values. The measured values of Tm, Yb, Lu, Hf, Ta, W, Re and Os are reported here for the first time. [Copyright &y& Elsevier]