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Intensity Ratio of Kβ/Kα in Selected Elements from Mg to Cu, and the Chemical Effects of Cr Kα1,2 Diagram Lines and Cr Kβ/Kα Intensity Ratio in Cr Compounds
Publication . Ito, Yoshiaki; Tochio, Tatsunori; Yamashita, Michiru; Fukushima, Sei; Shoji, Takashi; Słabkowska, Katarzyna; Syrocki, Łukasz; Polasik, Marek; Gomilsek, Jana Padežnik; Marques, José Pires; Sampaio, Jorge Miguel; Guerra, Mauro; Machado, Jorge; Santos, José Paulo; Hamidani, Assala; Kahoul, Abdelhalim; Indelicato, Paul; Parente, Fernando; LIBPhys-UNL; DF – Departamento de Física; MDPI - Multidisciplinary Digital Publishing Institute
(Formula presented.) X-ray lines from photon excitation were measured in selected elements from Mg to Cu using a high-resolution double-crystal X-ray spectrometer with a proportional counter, and the (Formula presented.) intensity ratio for each element was obtained, after correcting for self-absorption, detection efficiency, and crystal reflectance. This intensity ratio increases rapidly from Mg to Ca but, in the (Formula presented.) elements region, the increase becomes slower. This is related to the intensity of the (Formula presented.) line involving valence electrons. The slow increase of this ratio in the (Formula presented.) elements region is thought to be due to the correlation between (Formula presented.) and (Formula presented.) electrons. Moreover, the chemical shifts, FWHM, asymmetry indices, and (Formula presented.) intensity ratios of the Cr compounds, due to different valences, were also investigated using the same double-crystal X-ray spectrometer. The chemical effects were clearly observed, and the (Formula presented.) intensity ratio was found to be compound-dependent for Cr.
Fundamental parameters related to selenium kα and kβ emission x-ray spectra
Publication . Guerra, Mauro; Sampaio, Jorge M.; Vília, Gonçalo R.; Godinho, César A.; Pinheiro, Daniel; Amaro, Pedro; Marques, José P.; Machado, Jorge; Indelicato, Paul; Parente, Fernando; Santos, José Paulo; LIBPhys-UNL; DF – Departamento de Física; MDPI - Multidisciplinary Digital Publishing Institute
We present relativistic ab initio calculations of fundamental parameters for atomic selenium, based on the Multiconfiguration Dirac-Fock method. In detail, fluorescence yields and subshell linewidths, both of K shell, as well as Kβ to Kα intensity ratio are provided, showing overall agreement with previous theoretical calculations and experimental values. Relative intensities were evaluated assuming the same ionization cross-section for the K-shell hole states, leading to a statistical distribution of these initial states. A method for estimating theoretical linewidths of X-ray lines, where the lines are composed by a multiplet of fine-structure levels that are spread in energy, is proposed. This method provides results that are closer to Kα1,2 experimental width values than the usual method, although slightly higher discrepancies occur for the Kβ1,3 lines. This indicates some inaccuracies in the calculation of Auger rates that have a higher contribution for partial linewidths of the subshells involved in the Kβ1,3 profile. Apart from this, the calculated value of Kβ to Kα intensity ratio, which is less sensitive to Auger rates issues, is in excellent agreement with recommended values.
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Fundação para a Ciência e a Tecnologia
Programa de financiamento
3599-PPCDT
Número da atribuição
PTDC/FIS-AQM/31969/2017