Gamma back-scatter density/thickness measurements using Hp Ge detector

In the present work it is intended to study several physical parameters density and thickness for industrial application using γ-scattering technique. Employing γ-ray back- scattering techniques an experiment for material density determination has been constructed using 100 MBq Cs-137 gamma source and HPGe detector with effective volume 130 cc. Experimental geometry and radiation shielding are confined to allow detection of back scatter γ-rays from the sample volume interrogated by the radiation source and to prevent direct passage of the gamma-rays from the source to the detector. Hence, the available radiation source in the present work is Cs-137 with energy 882 KeV. The critical energy method is used. This method employs the detection of gamma-quantum energies related to the maximum of the scattered radiation. For elements having mass number less than 50. The critical energy method is based on a well-defined relation-ship. By using γ-γ density gauge. Calibration curves (I vs p) and (E vs p) have been obtained. Where I is the back-scatter response, E is the energy of the back scatter gamma-ray and p is the density of substance under investigation. These calibration curves should be made available. Blocks of dimension (50 x 40 x 20) cc. Of different samples are prepared. Some of which contain hydrogen (e.g.paraffin and wood) and others are free of hydrogen (e.g.graphite.iron and aluminium). The potentiality of such application is the study of the detector response for different elements in its respective mineral ores. Results obtained revealed the thickness and density effects upon the intensity and back-scatter energy of gamma-ray. The role of the high resolution HPGe detector is abvious in these measurements.3 fig