MODELING TERAHERTZ DIFFUSE SCATTERING FROM GRANULAR MEDIA USING RADIATIVE TRANSFER THEORY

Terahertz (THz) spectroscopy can potentially be used to probe and characterize inhomogeneous materials. However, identiflca- tion of spectral features from difiuse scattering by inhomogeneous ma- terials has not received much attention until now. In this paper, THz difiuse scattering from granular media is modeled by applying radiative transfer (RT) theory for the flrst time in THz sensing. The difiuse scat- tered fleld from compressed polyethylene (PE) pellets containing steel spheres was measured in both transmission and re∞ection modes using a THz time domain spectroscopy (THz-TDS) system. The RT model was validated by successfully reproducing qualitative features observed in experimental results. Difiuse intensity from granular media contain- ing lactose was then simulated using RT theory. In the results, spectral features of lactose were observed in the difiuse intensity spectra from the granular media.