Continuous Wave THz Imaging System for Defectoscopy of Polymeric Ferroelectric Materials

In this paper, the results of using the terahertz imaging system based on a reflectometer with a source continuous radiation to estimate the distribution of epoxy and barium titanate agglomerates (average size $\lt 100 \mu \mathrm{m}$ and 250-315 $\mu \mathrm{m})$ in the volume of composites are presented. The frequency dependences of the absorption coefficient of the composites were determined by the method of continuous wave and time-domain spectroscopy. It is shown that the absorption coefficient for a sample with the average size of barium titanate agglomerates $250-315 \mu \mathrm{m}$ is higher than for particles with a size less than $100 \mu \mathrm{m}$. Based on the measured distributions of the reflection coefficient from the composite, the homogeneity of the composite was estimated as a percentage depending on the average size of the ferroelectric agglomerates was estimated. It is shown that the defect area of the research composite sample with the size of the agglomerate of barium titanate particles $\lt 100 \mu \mathrm{m}$ is 22%, and in the sample with the size of the agglomerate $250-315 \mu \mathrm{m}$ is 45%.