Yusuf Sahin

Measurement of atomic L shell Coster-Kronig yields (f12, f23 and f13) for some elements in the atomic number range 59⩽Z⩽90

Non-radiative transitions cause changes in the generation of the intensity of the L lines. In order to investigate the physical quantities relevant to the L lines affected by the non-radiative transitions, experimental measurements were carried out using a Si(Li) x-ray spectrometer. Atomic L shell Coster-Kronig yields (f12, f13 and f23) for some elements in the atomic number range 59≤Z≤90 were determined. These selected measured semi-empirical values were also fitted by least squares to polynomials in Z of the form ∑nanZn (except for f13) and compared with theoretical and with earlier fitted values.

Determination of iodine and calcium concentrations in the bread improver using EDXRF

Abstract A study was made on the determination of elemental composition of the bread improver using energy-dispersive X-ray fluorescence. Enrichment of I and Ca was seen in the bread improver. Concentration of I with an annular 241 Am radioactive source and concentration of Ca with an annular 55 Fe radioactive source were determined by using standard addition method in 2 π geometry. A Si(Li) detector and a multichannel analyzer were used to measure I and Ca concentrations in the bread improver.

K and Ca content of fresh green tea, black tea, and tea residue determined by X-ray fluorescence analysis.

ZusammenfassungMit der X-Ray Fluoreszenztechnik können die qualitativen und quantitativen Bestimmungen der Mineralstoffe in verschiedenen Produkten erfolgreich durchgeführt werden. Mit dieser Methode wurde der Ca- und K-Gehalt von 138 Proben untersucht, und zwar frischer Tee, schwarzer Tee und Teerückstand. Diese Methode ist in der Lebensmitteltechnologie, insbesondere bei der Mineralstoffbestimmung nicht üblich. Die Teeproben stammten aus verschiedenen Teeanbaugebieten der Türkei. In dieser Arbeit wurden die Wirkung der Sproßperiode, der Verarbeitungstechnik und des Anbaugebietes auf den Ca- und K-Gehalt der Teeproben untersucht. Der durchschnittliche K-Gehalt betrug: in frischem Tee 19049–26254 mg/kg, in schwarzem Tee 21904–26883 mg/kg, in Teerückstand 9468–13778 mg/kg; der Ca-Gehalt 3580–4799 mg/kg, 3370–4823 mg/kg und 3473–5733 mg/kg.SummaryX-Ray fluoresence (XRF) can be successfully used for the qualitative and quantitative elemental analysis of various agricultural products. Its simplicity, high throughput and the possibility of automation make it useful for screening large numbers of samples. The K and Ca content of 138 samples of fresh green tea, black tea and black tea residues were determined by applying the XRF system. Such a method of mineral analysis of food products is not very common. Tea from different teagrowing areas of Turkey, green tea of different shooting periods, black tea processed at different tea plants and tea residues from these black tea were analysed. The K content of green tea, processed black tea and tea residues after brewing were found to have ranges of 19,049–26,254 mg/kg, 21,904–26,883 mg/kg and 9,468–13,778 mg/kg, respectively. In the same samples the Ca content was determined as 3,580–4,799 mg/kg, 3,370–4,823 mg/kg, and 3,743–5,733 mg/kg, respectively. These findings were compared with the results of atomic emission techniques and it was concluded that the XRF system could be effectively used for quantitative analysis of the K and Ca content of tea samples.

Coherent scattering of 59.5 keV photons by Au and Pb

Whole atom differential cross-sections for coherent scattering of 59.5 keV γ-rays by gold and lead were measured for angles ranging from 36° to 135°. A Ge(Li) detector was used to detect coherently scattered photons. The results were compared with that of different formalisms of form factor theory.

Monte Carlo Calculations of XRF Intensities in Annular Arrangements of Radioactive Source, Sample, Cylindrical Collimator and Detector

ABSTRACT A Monte Carlo (MC) computer program for the calculation of the distribution of characteristic X-ray intensities as a function of the counting geometry is described. The program evaluates the contribution to the intensities of a fluorescent line from each point of the source, sample and detector. The main considerations of the calculation are based on the critical nature of the internal geometry of the main analyzer components within an energy dispersive X-ray fluorescence (EDXRF) spectrometer. The K XRF intensities for the inner and outer radius of the annular-sample and collimator radius were measured. An optimum geometry can be obtained by varying the collimator radius and the detector-sample distance. The results of the calculations show that the intensity distribution of the radioisotope excited fluorescent radiation through annular sample area is strongly dependent on the collimator radius, with a maximum intensity effect with a smaller sample area and with decreasing collimator radius. An i...

Experimental studies on the coherent scattering of 59.5 keV γ-rays by Fe, Zn and Nb

A high-purity germanium detector was used to determine differential cross sections for coherent scattering of 59.5 keV γ-rays by Fe, Zn and Nb through angles from 55° to 105°. The results were compared with theoretical calculations.

Scattering of 59.5 keV γ-rays by Ti, Ni and Zr

ABSTRACT Incoherent scattering differential cross-sections have been experimentally determined for 59.5 keV photons in the angular range 36°-135° for the elements Ti, Ni and Zr. The experimental values have been compared with those estimated on the basis of the non-relativistic Hartree-Fock wave functions.

The Monte Carlo Calculation of the Solid Angle Subtended by a Circular Cylinder

Abstract The solid angle subtended at A point by a right circular cylinder is calculated by a Monte Carlo method. The five cases were analyzed using seven different events. The accuracy of the approximation has been evaluated by comparing the calculated solid angles with the tabulated values of literature. A good agreement is evident from the random number generated.

Efficiency Determination for NaI (Tl) Detectors in the 23 keV to 1333 keV Energy Range

Abstract The photopeak efficiency of a NaI (Tl) detector was determined experimentally for 23‐1333 keV photon energy by using polyester coated radioisotopes 22Na, 54Mn, 57Co, 60Co, 109Cd, 137Cs, and 133Ba. The energy resolution of the NaI (Tl) detector was also measured. The data were analyzed using the Genie‐2000 from Canberra. The experimental values were fitted to an analytical function of photon energy and an agreement was observed for the entire range of the studied energies. The results have shown that the NaI (Tl) detector is a particularly attractive detector for field application, as it works at room temperature and has a high probability of detecting gamma radiation.

Coherent Scattering of 59.5 keV γ-rays by Ti, Ni, Zr and In Through Angles from 36° to 135°

ABSTRACT A high-resolution lithium-dnfted germanium detector was used to determine the differential cross-sections for the coherent scattering of 59.5 keV γ-rays by titanium, nickel, zirconium and indium through angles from 36° to 135°. The experimental cross-sections are compared with predictions of the nonrelativistic, relativistic and relativistic modified form factor theories. The best agreement is obtained for the relativistic and relativistic modified form factor theories.