Gamma ray attenuation coefficients of carbon steel material using D7 film and ion chamber detectors / Wan Siti Aishah Wan Zukepeli

Attenuation coefficients (//) are the probability of a radiation interacting with a material. Measurement of gamma radiation attenuation coefficients on carbon steel material has been made for material studies and industrial applications. The attenuation coefficients of the material were determined, at constant energy using gamma radiation emitted from a point source of 25 Ci and 1.94 Ci of Iridium-192. The material used has various thicknesses ranging from 0.3 to 1.0 cm. Two types of detectors were used; D7 film and ion chamber. Different detectors are significant to determine the consistency of the attenuation coefficients for the same material. The material was collimated with lead sheets. Broad beam of gamma radiation was used for both experiments. The beam geometry affects the recorded number of photons due to scattering processes. Optical densities in film radiography were obtained for the exposed films and unabsorbed radiation density. Radiation intensities for the attenuated and unabsorbed radiation were obtained directly in ionization radiography. These parameters were then used to determine attenuation coefficients of the material using Beer' s\Lambert law. The coefficients are found to be exponentially decreased with thickness. The change in attenuation coefficients obeyed the Beer's Lambert law. Comparison fi coefficients between film and ion chamber shows a high percentage difference in range 61% to 74%.