Use of effective medium theory for characterization of optical and dielectric properties of explosive composites in terahertz spectral range

This paper reports the optical and dielectric characterization of highly sensitive explosives composites using an Effective Medium Theory approach in Terahertz Time-domain Spectroscopy. For the spectroscopic studies, samples need to be in pellet form. However, making pellets of some of the primary shock-sensitive high-energy materials is risky due to their sensitivity to grinding. Therefore, these sensitive samples must be mixed with an external host medium (Teflon) to form a pellet. We have approached Effective Medium Theory (EMT) analytic relations, such as Maxwell Garnett, Bruggeman, and LLL approaches, to extract the optical and dielectric properties from Teflon/ sensitive explosive composite. The approach was validated by preparing a mixture of three premium explosives, RDX, HMX, and TNT, in a Teflon matrix and extracting their optical and dielectric properties using the Effective Medium Theory method. The obtained properties of the explosives were then compared with those of the pure explosives (without the Teflon matrix). The extracted values show good agreement with those of the pure samples for the explosive mixture in the Teflon matrix (1:5).