Two-Frequency Planar Gradiometer for Distant NQR Detection of Explosives

Abstract

The experimental realization of the two-frequency N-14 nuclear quadrupole resonance (NQR) technique with use of the gradiometer radiofrequency (RF) probe for applications in the remote detection of explosives and other substances has been proposed. The planar two-frequency gradiometer has been designed, modeled and manufactured. The regions, where the RF magnetic fields are nearly orthogonal to each other, have been determined by finite-element modeling studies. The two-frequency experiments have been carried out for the detection of hexahydro-1,3,5-trinitro-s-triazine C3H6N6O6 (RDX). The possibility of the combined use of the two-frequency N-14 NQR technique and the gradiometer RF probe in practice for detection of explosives hidden under clothes or underground has been also discussed.