Uğurlu, Mine; Akkuş, Tuba; Akbulut, Ozan; Demir, Lütfü; Yılmaz, Demet

In this study, full widths at half maximum (FWHM), asymmetry indexes, chemical shifts (ΔE) and Kβ-to-Kα X-ray intensity ratios of some pure metals (Mn, Fe, Cu and Zn) and some of their oxidized compounds (Mn2O3, Fe2O3, Fe3O4, Cu2O3 and ZnO) were investigated. The samples were excited by 59.54 keV photons emitted from a241Am radioisotopes source and characteristic K X-rays emitted from the samples were counted by a Si(Li) detector. The results have shown that the Kβ-to-Kα X-ray intensity ratios, asymmetry indexes, chemical shifts and full widths at half maximum (FWHM) values can change with sample sizes.

Yılmaz, Demet; Akkuş, Tuba

In this study, the albedo factors (number, energy, and dose) of some boron compounds were investigated at a scattering angle of 180°. Eight boron compounds were tested in the mean atomic number range of 4.571 ≤ Z‾ ≤ 19.00. The samples were irradiated by gamma rays emitted at 59.54 keV from an Am-241-point source with an activity of 0.43 MBq. The scattered gamma rays were counted by an ultra-low energy germanium detector with a resolution of 140 eV at 5.9 keV. The results showed that the albedo factors decreased as the mean atomic number increased. The correlations between the albedo factors and mean atomic numbers were also high.

Akkuş, Tuba; Yılmaz, Demet

In this work, the qualitative analysis has been performed by using ratio of coherent to backscattering intensity ratios. The samples in the mean atomic number range 4.268≤Z‾≤5.786 and 9.743≤Z‾≤83.00 were prepared by using dilution technique. 59.54 and 661.62 keV photon energies are obtained from the radioactive point sources of 241Am and 137Cs an activity of 0.43–0.20 MBq, respectively. The scattered gamma rays were counted by a HPGe detector with a resolution of 182 eV at 5.9 keV. The obtained intensity ratios are plotted as function of the mean atomic number and constituted a best-fit-curve. The correlation coefficients for the prepared samples in the mean atomic number range 4.268≤Z‾≤5.786 are 0.976 and 0.970 at 59.54 and 661.62 keV photons, respectively. The correlation coefficients for the prepared samples in the mean atomic number range 9.743≤Z‾≤83.00 are 0.964 and 0.967 at 59.54 and 661.62 keV photons, respectively. It is observed that there was a high correlation between coherent to backscattering intensity ratio and the mean atomic numbers. It was concluded that the recommended intensity ratio can be used for qualitative analysis.

Akkuş, Tuba; Yılmaz, Demet

The albedo factors (number, energy and dose) of the samples with various mean atomic number have been investigated at a scattering angle of 180°. Fourteen different samples in the mean atomic number range 9.743 ≤ Z‾ ≤ 83.00 were obtained with bismuth and cellulose powders by using dilution technique. Thus, albedo factors have been investigated in a wide atomic number range. The samples were irritated by 662 keV gamma rays emitted from a137Cs radioactive source. The scattered γ -rays were counted by an HPGe detector with active area of 200 mm2. It has been observed that albedo factors decrease with increasing mean atomic number. Also, there is a high correlation between albedo factors and mean atomic numbers.

Akkuş, Tuba; Uzunoğlu, Zeynep; Yılmaz, Demet

The variation of different intensity ratios with mean atomic number for qualitative analysis was investigated in EDXRF. Ten different samples with a mean atomic number between 4.268 and 5.786 were obtained by mixing zirconyl chloride octahydrate (Cl 2 OZr·8H 2 O) and cellulose (C 6 H 10 O 5 ) powders. The samples were excited by 59.54 keV gamma rays emitted from a 241 Am annular radioactive source with 5 Ci activity. The high purity germanium (HPGe) semiconductor detector with a resolution of 182 eV at 5.9 keV was used to detect the photons. (I coh /2(μ/ρ) λ +I comp /(μ/ρ) λ +(μ/ρ) λ−Δλ ), (I coh +I Comp )/(μ/ρ) λ , (I coh /2(μ/ρ) λ , I Kα /I sc and I Kβ /I sc intensity ratios in XRF spectrum for the assessment of information regarding the mean atomic number of the samples are studied. It has been observed that the total scattering intensity ratios can be used with high reliability in qualitative analysis for complex materials.

Akkuş, Tuba; Alım, Bünyamin; Yılmaz, Demet; Şahin, Yusuf

L X-ray differential cross-sections of uranium were calculated at several polar scattering angles (85°, 95°, 105°, 115°, 125°, and 135°) at 59.54-keV photon energy by using a Si(Li) detector. We observed that Ll and Lα X-rays were dependent on the polar scattering angle, whereas Lβ and Lγ X-rays were independent of the polar scattering angle. Therefore, the anisotropy parameters for Ll and Lα X-rays were obtained using the intensity ratios of Ll to Lγ X-rays and of Lα to Lγ X-rays to reduce some systematic errors.

Yalçin, P.; Kurucu, Y.

Emission probabilities of K X- and γ-rays following the decay of 51Cr and 67Ga were precisely measured with a calibrated Si(Li) detector. The photopeak efficiency of the Si(Li) semiconductor detector was determined experimentally for about 4-400keV energy range by using standard sources. Results of this study have been compared with the theoretical values and other available experimental results in the literature. Good agreement was observed between our results, and other available experimental results and theoretically calculated values.