Interaction of an electromagnetic wave with the surface of a real explosive substance.

To develop the theoretical basis for the effective detection and neutralization of explosive substances using electromagnetic radiation. The problem of detecting explosives is extremely relevant in the modern world. The development of new methods based on the physical principles of the interaction of electromagnetic radiation with matter is a promising area of research. An electrodynamic model of the interaction of an electromagnetic wave with the surface of a VR has been developed. The model takes into account an arbitrary angle of incidence of the wave and two main polarizations – TM and TE. Maxwell’s equations with the corresponding boundary conditions at the interface between two media (air – explosive substance) were used to solve the electrodynamics problems. Different types of explosive substances with different dielectric properties were considered as objects of study. To solve the problem, numerical modeling based on the finite difference method was used. The modeling allowed us to calculate the energy coefficients of reflection, refraction, and absorption of electromagnetic radiation by the explosives. It was found that the efficiency of interaction of an electromagnetic wave with a radiation source significantly depends on the angle of its incidence. The optimal incidence angle for most of the studied radiation sources is in the range of 60 to 75 degrees. For the VRs with low dielectric losses, the influence of the dielectric loss tangent on the imaginary part of the refractive angle is insignificant. This indicates that for such materials the main mechanism of interaction is the reflection of an electromagnetic wave. It has been shown that the energy refractive index has a local extreme (maximum) in the range of incident angles from 65 to 85 degrees. The energy reflection coefficient for a plane electromagnetic wave with vertical polarization increases with the increase of the real part of the relative permittivity according to a law close to the logarithmic law for incident angles less than 60 degrees.