Development of Gamma-based Nondestructive Testing System for Thickness Measurement

Abstract

In this work, a simple gamma transmission-based non destructive system has been developed for scanning thickness defects in flat rolled products and discriminated samples with respect to their density. Based on radiation attenuation, the study involved the measurement of the thickness in centimeters scales for a flat sheets of Alumina ceramic, borated glass, aluminum and iron. The practicality of using the system to detect thickness flaws in millimeter range was calculated considering a scenario that a thickness change by 1mm is present along the sheet of each sample. This is done through the assessment of the degree of transmitted attenuation experienced by a beam of high energy ionizing radiation, such as 241Am directed perpendicular to the planar surface of the material. The results confirmed the sensitivity of the system for detection of flaws in both thickness scales. On the other hand, the performance of the proposed system in discriminating between the four samples was investigated. The results showed that, for Alumina ceramic, borated glass, aluminum and iron, the transmitted flux peaks at the energies, 13 KeV, 40 KeV, 20 KeV and 17 KeV, respectively. These results suggest the possibility of using such v energies to identify each of the four samples used.