Naslov
Influence of K-edge absorption on Kβ x-rays of Ti, V, Cr and selected compounds induced by the proton impact

Autori
Fazinić, S ; Božičević, I ; Tadić, T ; Mandić, L

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Program and Book of Abstracts, EXRS 2012 / Christina Streli, Andrzej Markowicz - Beč : Technische Universitat Wien, 2012, 228-228

Skup
European Conference on X-ray Spectrometry

Mjesto i datum
Beč, Austrija, 18.06.2012. - 22.06.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
K-edge absorption, Ti Kbeta X-rays, V, Cr

Sažetak
Recently we performed simple parametrization of Kβ′ ′ and Kβ2, 5 x-rays' relative positions and intensities over the range of 3d metal compounds [1]. The parametrization was based on high resolution spectra from thick targets measured by two wavelength dispersive x-ray spectrometers (WDS) capable to resolve Kβ x-ray band into several visible components, including the main Kβ1, 3 line and second order contributions Kβ', Kβ'', Kβ2, 5, and KβL1 [2, 3, 4]. As excitation, 2 and 3 MeV protons were used. We hope that the parametrization obtained could be useful for improved interpretation of K x-ray spectra of 3d transition metal compounds measured by solid state detectors, since reliable Kβ/Kα intensity ratios are essential for x-ray spectroscopy methods, PIXE being the one where proton beams are used as excitation source. The measured high-resolution WDS spectra from thick metallic targets showed asymmetric Kβ2, 5 lines with sharper (narrower) high-energy wing. This could be due to their location very close to the K-shell absorption edge. Kβ2, 5 peaks in measured oxides did not show visible asymmetric behavior, although compounds with tetrahedral coordination have strong absorption pre-peaks in related XANES spectra close to the Kβ2, 5 peaks. In order to estimate the influence of K-edge Kβ self-absorption to thick-to-thin target yield ratios, we used experimental XANES data of Ti, V, Cr and related compounds to estimate absorption coefficients very close to the absorption edge. Comparison of published XANES spectra showed differences in energy calibrations which lead to uncertainties in calculated thick-to-thin target yield ratios for Kβ2, 5 emission line, especially for metallic and tetrahedraly coordinated compounds. In order to resolve these uncertainties and investigate the influence of the K-edge on self-absorption of Kβ x-ray band components more precisely, we measured K x-rays from Ti, V, Cr, and their selected compounds with and without Ti, V, Cr absorber foils of appropriate and well known thickness. Corresponding K x-ray spectra were also measured with standard Si(Li) detector with and without absorbers. Having in mind that the intensity of the strongly absorbed multiple-ionization satellite KβL1 is proportional to the ionization cross section for simultaneous ionization of K- and L-shells, which depends on the proton beam energy, the measurements have been performed by proton beams at several selected energies. The measured spectra have been analyzed and the results discussed. [1] S. Fazinić, L. Mandić, M. Kavčič, I. Božičević. J. Anal. At. Spectrom. 26 (2011) 2467. [2] S. Fazinić, L. Mandić, M. Kavčič, I. Božičević. Spectrochimica acta Part B 66 (2011) 461. [3] L. Mandić, S. Fazinić, M. Jakšić. Phys. Rev. A80 (2009) 042519. [4] S. Fazinić, M. Jakšić, L. Mandić, J. Dobrinić. Phys. Rev. A74 (2006) 062501.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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