Egyptian limestone for gamma dosimetry: an electron paramagnetic resonance study

The electron paramagnetic resonance (EPR) properties of limestone from a certain Egyptian site were investigated in order to propose an efficient and low-cost gamma dosimeter. Radiation-induced free radicals were of one type which was produced in the limestone samples at g=2.0066 after exposure to gamma radiation (⁶⁰Co). EPR spectrum was recorded and analyzed. The microwave power saturation curve and the effect of changing modulation amplitude on peak-to- peak signal height were investigated. The response of limestone to different radiation doses (0.5–20 kGy) was studied. Except for the decrease in signal intensities during the first five hours following irradiation, over the period of two months fair stabilities of signal intensities were noticed. From the current results, it is possible to conclude that natural limestone may be a suitable material for radiation dosimetry in the range of irradiation processing.