Terahertz Differential Computed Tomography: a Relevant Nondestructive Inspection Application

Alexandre Duhant (1, 2) , Meriam Triki (1) , Olivier Strauss (2)

1 Terakalis
2 ICAR - Image & Interaction

In recent years, tremendous advances have been made in the choice of materials used in industry. With weight reduction as the goal, composite and polymer materials are more and more popular but they are almost transparent to X-ray. Because of this, interest has grown in other wavelengths like TeraHertz (THz). Due to a difference in how X-ray and THz propagate, X-ray CT algorithms cannot be directly used. For example, THz induces refraction making the reconstruction problem nonlinear. In this paper, we present a new algorithm which complies with beam profile intensities, refraction, reflection. It is based on linearizing the reconstruction process around a Computer Aided Design (CAD) model of the object to be reconstructed. The method we propose computes the deviation between the object and this model.

Mots clés: Nondestructive testing; Terahertz computed tomography; Refraction; Nonlinear problem; Modeling; Projection simulation; Monte Carlo; Inverse problem

Domaines: Modélisation et simulation

Alexandre Duhant, Meriam Triki, Olivier Strauss. Terahertz Differential Computed Tomography: a Relevant Nondestructive Inspection Application. Journal of Infrared, Millimeter and Terahertz Waves, 2019, 40 (2), pp.178-199. ⟨10.1007/s10762-018-0564-5⟩. ⟨hal-01968434⟩