Experimental and theoretical investigation of gamma attenuation for soil and oil soil samples

The gamma rays attenuation is investigated experimentally and theoretically for soil and oil soil samples. The soil samples were collected from different locations of Kirkuk city in Iraq and the oil soil samples which are soil samples contaminated with oil were collected from different locations in surrounding areas of Kirkuk oil field. The experimental measurements have been investigated using gamma spectrometer multichannel analyzer MCA contains shielded NaI (Tl) detector. The collimator of aperture diameter 3 mm were used to ensure that the detector absorbs a narrow beam of gamma rays after passing through the test column. Samples were irradiated by gamma-rays emitted from point sources of ²⁴¹Am, ¹³³Ba, ¹³⁷Cs and ⁶⁰Co. The attenuation coefficients were also calculated theoretically using XCOM software and Monte Carlo simulation code Geant4. To evaluate the availability of the codes, the comparisons with the experiments are presented.