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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]