Önder Kabadayi

Calculation of average projected range and range straggling of charged particles in solids

Abstract Based on the KRAL equations (Ashworth et al., 1991. J. Phys. D 24, 1376–1380), which take into account second-order energy loss moments, projected ranges and range moments of ions in mono-atomic targets were calculated. For this purpose, the set of three coupled differential equations of second order was first reduced to a set of differential equations of first order, and solved afterwards numerically, using initial values with respect to the electronic stopping power according to Montenegro et al. (1981) which are valid at non-relativistic velocities in all solid targets and are consistent with experimental data for a wide range of energies. The numerical solution of the KRAL equations was performed by applying a continuous Runge–Kutta method of seventh–eighth order and a Fehlberg Runge–Kutta method of fourth–fifth order. The results with respect to the projected ranges of Xe ions in amorphous Si are in a good agreement with measured data, and those with respect to the projected ranges and range straggling of H or B ions in amorphous Si with data calculated by the standard theories TRIM, PRAL 97 and WS (Wang and Shi, 1990. J. Phys. D 23, 1282–1289).

Natural radioactivity levels in lake sediment samples

The radioactivity concentrations of nuclides (238)U, (232)Th and (40)K in lake sediments collected from 15 different stations at Altınkaya dam lake and 12 different stations at Derbent dam lake in Turkey were measured using high-resolution gamma-ray spectrometry. The measurement was done using a coaxial HPGe detector system coupled to the Ortec-Dspect jr digital MCA system. The average measured activity concentrations of the nuclides (238)U, (232)Th and (40)K were found to be 19.5, 27.7 and 460 Bq kg(-1) in Altınkaya dam, whereas the activity concentrations were 18.8, 25.5 and 365 Bq kg(-1) in Derbent dam, respectively. The measured activity concentrations in the present study have been compared with similar measurements from different locations in the world.

Natural activity concentrations in bottled drinking water and consequent doses

The radioactivity concentrations of nuclides (238)U, (232)Th and (40)K in bottled drinking water from six different manufacturers from Turkey were measured using high-resolution gamma-ray spectrometry. The measurement was done using a coaxial high-purity germanium detector system coupled to Ortec-Dspect jr digital MCA system. The average measured activity concentrations of the nuclides (238)U, (232)Th and (40)K are found to be 0.781, 1.05 and 2.19 Bq l(-1), respectively. The measured activity concentrations have been compared with similar studies from different locations. The annual effective doses for ingestion of radionuclides in the water are found to be 0.0246 mSv for (238)U and 0.169 mSv for (232)Th.