A novel approach for constructing the calibration curve applied in determining the thickness of different types of materials

A solution using a gamma-ray beam to measure the thickness of materials with different elemental composition is necessary as this issue has not been previously addressed. Traditionally, a linear calibration curve is only utilized to determine the thickness of a specific material. This means that multiple separate calibration curves must be used when measuring the thickness of different types of materials, which results in increased time and cost. This study proposes a novel aproach for constructing calibration curves that can be applied to measure the thickness of materials with different elemental composition. The methodology and mathematical formalism are described. For each material type, the linear calibration curve (LCC) of lnR (R represents the ratio of areas under the transmission peak for measurements with and without a sample) versus thickness of material plate has been constructed. The slope of this linear calibration curve, depending on the linear attenuation coefficient (LAC) of the material, enables easy determination of material thicknesses. To assess accuracy, we conducted thickness measurements on reference material plates including aluminum, steel, copper, and graphite. The obtained results indicate that relative deviations between measured and reference thicknesses are below 2.39%, confirming the usefulness and reliability of the proposed approach in measuring thickness for different types of materials.