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Influence of K-edge absorption on Kβ X-ray spectra of Ti and V induced by the proton impact

Our recent analysis of experimental high-resolution Kβ PIXE spectra from thick Ti, V, Cr and Mn metallic targets showed asymmetric Kβ2, 5 lines with sharper (narrower) high-energy wing. This could be due to their partial self-absorption in the target due to their location very close to the K-shell absorption edge. In case of these elements, multiple ionization satellites (KβLm) are heavily affected by the fine structure of the absorption edge since their energy is just above the K-edge. In order to estimate the influence of K-edge Kβ self-absorption to thick-to-thin target yield ratios, we used related experimental XANES data to estimate absorption coefficients very close to the edge. However, the comparison of published XANES spectra showed differences in energy calibrations which could lead to uncertainties in calculated thick-to-thin target yield ratios for Kβ2, 5 and KβLm components. In order to resolve these uncertainties and investigate the influence of the K absorption-edge on self-absorption of Kβ X-ray band components (Kβ2, 5 and KβLm) more precisely, we measured K X-rays of thin and thick Ti, V and their selected compounds with and without respective absorber foils of appropriate and well known thickness, using both high resolution and low resolution spectrometers. The spectra obtained by low resolution spectrometer (standard Silicon Drift Detector) were used to study absorption of multiple ionization satellites, and high resolution spectra (obtained by the wavelength dispersive spectrometer) were used to analyze the influence of the K-edge on Kβ2, 5 absorption. The measured spectra have been analyzed and the results discussed.

high-resolution spectra; Kβ fine structure; K-edge; Ti; V; multiple ionization satellites; self-absorption

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