Features of using the Comsol Multiphysics software for modeling a spiral antenna of an NQR detector

The paper considers the review of important points of using the Comsol Multiphysics software for modeling a spiral antenna of an NQR detector of explosives and narcotic substances. The center frequency at which the simulation was performed is 3.41 MHz, which corresponds to the NQR detection frequency of sodium nitrite. It was found that the best results were demonstrated by a model with five turns, an inner radius of 25 mm, an outer radius of 225 mm, made of a copper tube with an outer diameter of 10 mm and an inner diameter of 9 mm.