EFFECTIVE RADIUM CONTENT IN EGYPTIAN SOIL BY CR-39 AND LR-115 PLASTIC NUCLEAR TRACK DETECTORS

CR-39 and LR-115 plastic detectors were used in air volume of several sealed cylinderical plastic tubes (can-technique) for time integrated long term measurement of radon activity concentrations. Dried soil samples, collected from the Egyptian Nile delta, were used. The tubes, 3.8 cm inner diameter and 20-170 cm in heights, were filled at the bottom with the dry soil samples up to different thicknesses (10-160 cm). The registeration sensitivities of CR-39 and LR-115 nuclear plastic detectors in the sealed tube, taking into consideration the plated-out activity on the walls, are discussed. The porosity of the soil samples, the diffusion length, the effective and real radium-226 contents were estimated. The results showed that the sealed tube technique could be used as a useful tool for the measurement of the radium concentration with reasonable accuracy.