Hüseyin Ali Yalım

Comparison of radon concentrations in soil gas and indoor environment of Afyonkarahisar Province

It is well known that radon is the main source of natural radiation exposure to the population. Indoor radon concentrations in an area are affected by ascending radon migration following the convection of groundwater and soil gas along fractures and faults in the bedrock sediments. There are various studies showing that positive radon anomalies in the soil gas are found to coincide with the locations of houses showing the highest concentrations. Moreover, soil gas radon levels and soil permeability are important factors in determining the radon potential of an area, because high permeability enables the increased migration of radon from the soil into houses. Since radon in homes originates mainly from soil gas radon, it is of public interest to study the correlation between soil gas radon and indoor radon in different geographic locations. In the present work, a correlation study was carried in conjunction with radon concentrations in soil gas and indoor environment of Afyonkarahisar Province. The provincial center was assumed to be divided into four regions according to the rock types and tectonic structure to show also the geological structure effect on radon concentrations. The indoor radon concentrations were measured in 74 dwellings using CR-39 passive nuclear track detectors, and the radon concentrations in soil gas were determined in 243 drilled holes using AlphaGUARD detector. The correlation coefficient of 0.97 was obtained between radon concentrations in soil gas and indoor environment of Afyonkarahisar Province.

Comparison of level density models in (γ, n) reactions of some lanthanide nuclei

Level densities are required at excitation energies where discrete level information is not available or incomplete to get a reliable theoretical analysis of cross sections, spectra, and angular distributions. The total reaction cross sections of some lanthanides (141Pr, 142Nd, 144Sm, 153Eu, 160Gd, 159Tb, 165Ho, 175Lu) were calculated using TALYS 1.2 code for gamma-induced reactions through the five level density models in the incident gamma energy range from 5 to 30 MeV. All calculations from the present study were compared with each other and with the experimental data obtained from EXFOR library. The total photo-neutron reaction cross-section values obtained from the model calculations and experimental measurements taken from EXFOR confirm the presence of systematical disagreements reported in the literature, except 165Ho case where one can see a satisfactory agreement.