E. Tıraşoğlu

Angular Dependence of Differential Cross-Sections of L X-Rays from Hg, TI, and Pb at 59.5 keV

Introduction According to Cooper and Zare [l], spatial distribution of X-ray emission for different magnetic substrates is always isotropic, but in the theoretical calculations of Flugge et al. [2], it is shown that spatial distribution of X-rays is different for different magnetic substrates. The Xrays originating from the states corresponding to J = 1/2 (K shell and L1, L2, M1, M2, subshell, etc.) are expected to be isotropic and those corresponding to state J = 3/2 (L2, M3, M4, subshell, etc.) and J = 5/2 (M5 subshell, etc.) are expected to be anisotropic in their spatial distribution. The angular distributions of ion-induced [3–7] and photon-induced [8–10] L X-rays were investigated for some elements. We have measured differential cross-sections of L shell X-rays from Hg, T1, and Pb at different angles varying from 45° to 135° at 15° intervals.

Measurement of K to L shell vacancy transfer probabilities for the elements 52⩽Z⩽68

Abstract The probabilities for transfer of vacancies from K to L shell were measured using intensity ratio of Kα and total Lx X-rays. The Kα and total Lx X-rays yields from the targets excited by 59.5 keV incident photon were obtained using a Si(Li) detector. These experimental results were compared with the theoretically calculated values using radiative and radiationless transitions. The radiative transitions of these elements were observed from the relativistic Hartree–Slater model, which was proposed by Scofield (Atom. Data Nucl. Data Tables 14 (1974) 121). The radiationless transitions were observed from the Dirac–Hartree–Slater model, which was proposed by Chen et al. (Atom. Data Nucl. Data Tables 24 (1979) 13). A fairly good agreement is found between the experimental and calculated values.

Empirical, Semi-Empirical and Experimental Determination of K X-Ray Fluorescence Parameters of Some Elements in the Atomic Range 21 ≤ Z ≤ 30

In this study, the semi-empirical and empirical calculations of K X-ray intensity ratios, K-shell fluorescence yields, and vacancy transfer probabilities have been performed for 3d transition elements. Also, σKα, σKβ production cross-sections, Kβ/Kα intensity ratios, ωK fluorescence yields, and ηKL vacancy transfer probabilities of 3d transition elements have been measured. The samples were excited by 59.5 keV γ-rays from a 241Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV.

An LIII (2P3/2) subshell absorption jump ratio and jump factor for bismuth

In this paper, we report on measurement of the first experimental LIII (2P3/2) subshell absorption jump ratio and jump factor value which were derived from new mass attenuation coefficients measured at the upper and lower energy branches of the LIII absorption edge using an energy dispersive x-ray fluorescence (EDXRF) spectrometer for bismuth. The measurements of mass attenuation coefficients, at 36 energies from 10.010 to 17.478 keV, were done in a transmission geometry utilizing the Ki (i = α, α1,2, β, β1,2) and Li (i = α, β, β1,2, γ, γ1, l) x-rays from different secondary source targets excited by the 59.543 keV γ-photons from an 241Am annular source and detected by an ultra-LEGe solid-state detector with a resolution of 0.15 keV at 5.9 keV. The results have been compared with theoretical values.

Chemical effect on the K and L shell intensity ratios of Hf compounds

Chemical effects on the Ki/Kj (i=α2, β, β1, β2; j=α, α1, β1), Li/Lα (i=l, β, γ) and Li/Kj (i=l,α, β, γ; j=α1, α2) x-ray intensity ratios for  (Hf) compounds were investigated. The samples were excited by 123.6 keV γ-rays from a 57Co annular radioactive source. K and L x-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. We observed a chemical effect on the Li/La and Li/Kj x-ray intensity ratios for Hf compounds. However, for the Ki/Kj intensity ratios, dependence on the chemical state of Hf compounds is almost negligible. The experimental values have been compared with the theoretically calculated values of pure Hf.

LEVELS OF CESIUM RADIONUCLIDES IN LICHENS AND MOSSES FROM THE PROVINCE OF ORDU IN THE EASTERN BLACK SEA AREA OF TURKEY

Chemobyl nuclear power plant accident in Ukraine in April 26, 1986 has affected Scandinavia and European countries, the Balkans and the northside of Turkey. Radioactive clouds depending on meteorological conditions had contaminated soil surface and flora in the region of Thrace and the seaside of the Black sea. This study has been done on mosses and lichens in which radioactive isotopes can live for a long time. These specimens have been collected in various regions of Ordu located in the Eastern Black Sea region of Turkey. On the basis of the results of this study the geographic distribution of pollution on the flora has been done.

Investigation of Coster-Kronig Transition Probabilities (L1 ! L2, L1 ! L3, and L2 ! L3) for Hf and Hf Compounds

In this study, the L 1 →L 2 , L 1 →L 3 , and L 2 →L 3 Coster–Kronig (CK) transition probabilities ( f 12 , f 13 , and f 23 ) for Hf compounds were investigated. The samples were excited by 59.5 keV γ-rays from a 241 Am annular radiative source. L X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. In addition, it was observed a chemical effect on the CK transition probabilities for Hf compounds. The semi-empirical values of f 12 , f 13 , and f 23 CK transition probabilities have been compared with the semi-empirical, theoretical and experimental data for pure Hf, respectively.

Investigation by XRF and XRD of Zn and Fe in Fex Zn1−x thin films

FexZn1?x alloys were electrochemically deposited on aluminum substrates from a sulfate bath. The K?/K? x-ray intensity ratios of Zn and Fe in FexZn1?x thin films have been experimentally studied. The energy dispersive x-ray fluorescence (EDXRF) technique was used to measure K x-ray photons. Samples were excited by using 59.5?keV photons emitted by a 50 mCi 241Am radioactive source. The emitted K x-rays were detected by an Ultra-LEGe detector having a resolution of 150?eV at 5.9?keV. In addition, the effect of bath composition on the phase structure was investigated by x-ray diffraction (XRD) analysis. The composition of the thin films was analyzed by atomic absorption spectrometry analysis. Iron content was shown to strongly affect the structure of Zn?Fe alloys. It was found that the K-shell x-ray intensity ratio changed in FexZn1?x thin films for different values of x. The reason for this change may be that the electronegativity of iron is higher than that of zinc and that electron transfer from zinc to the outermost orbital of iron occurs. In conclusion, in FexZn1?x thin films, intensity ratio increases with increasing concentration of Zn but decreases with increasing concentration of Fe.

L shell X-ray fluorescence parameters of Pb in phthalocyanine complexes

The L shell X-ray intensity ratios Li/Lα (i=l, β and γ), the production cross-sections σ(Li) (i=l, α, β and γ) and the L3 subshell fluorescence yields ω(L3) have been investigated for the element Pb in the phthalocyanine complexes. The measurements have been performed using an (241)Am annular radioactive source and an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. The experimental values have been compared with the theoretical values of pure Pb element.

MEASUREMENT OF THE ENHANCEMENT EFFECT IN DIFFERENT SAMPLE SERIES IN X-RAY FLUORESCENCE ANALYSIS

The dependence of the enhancement effect on the element concentration in the sample matrix has been investigated by energy dispersive X-ray fluorescence analysis. The values of the enhancement effect factors for La2O3–Pr6O11–Sm2O3, La2O3–Sb–Eu2O3, and La2O3–Sm2O3–Gd2O3 at 59.5 keV incident photon energy have been measured.