Thickness measurement analysis of metals sheets based on gamma densitometry using MCNPX code

Abstract

This report presents a gamma radiation-based study employing two main detection techniques, named dual energy and dual modality, and find how they perform to measure the thickness of 3 different metal sheets: aluminum, iron and copper. In order to evaluate the difference between the two techniques and which of them would give the best results to get the thickness of different metal sheets, the simulations were performed using MCNPX code as follows: 1 - using two radiation sources (¹³⁷Cs and ⁶⁰Co) and one NaI (Tl) detector; 2 - using one radiation source (¹³⁷Cs) and two NaI(Tl) detectors.