Determination of LIII subshell photoelectric parameters of iridium

The LIII 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 http://physics.nist.gov/xcom . 2005) and FFAST (Chantler et al. X-ray form factor, attenuation and scattering tables (version 2.1). NIST. Available at http://physics.nist.gov/ffast . 2005).

Measurement of anomalous scattering factors of tin using characteristic X-ray photons

The imaginary and real parts of anomalous scattering factors of Sn atoms around the K shell binding energy are measured using K and L X-ray photons. Gamma photons of energy 59.54 keV from an Am-241 radioactive source are used to excite K and L X-ray photons of various energies. By measuring the intensities of incident and transmitted X-ray photons in Sn foil with a good geometry arrangement, the K shell photoelectric cross sections are determined around the K shell binding energy of Sn. The real and imaginary parts of anomalous scattering factors of Sn are determined from K shell photoelectric cross section values. Experimentally determined form factors are compared with the theoretical prediction and experimental data obtained with synchrotron source.

Total-to-K-shell photoelectric cross-section ratios in some rare-earth and high-Z elements

The total photoelectric cross-sections in the elements gadolinium, dysprosium, erbium, lutetium, tantalum, tungsten, gold, and lead have been obtained by using the normal transmission experiments, and the results are reported. Using these total photoelectric cross sections, we have found the K-shell photoelectric cross sections, the K-jump ratios, and the total-to-K-shell photoelectric cross-section ratios at the K edges for the above elements. These values are compared with the available theoretical and experimental values. The results are in good agreement with the Storm and Israel results and the Scofield theoretical values, within the limits of experimental uncertainties. Furthermore, the variation of the total-to-K-shell photoelectric cross-section ratio with energy and atomic number is discussed.