A Two-Spiral Flat Coil for Detecting 14N NQR Signals

Abstract

621.396.67In the present article, the design of a two-spiral flat coil intended for detecting NQR signals is described. Results of calculations of its magnetic fields and field non-uniformities are presented for windings of different types. It is demonstrated that the two-spiral coil field is localized in the near-field zone and has more uniform structure than the field of the conventional spiral coil with the same radius and winding type. It is emphasized that the two-spiral coil has higher sensitivity than the analogous conventional flat coil. Results of experiments on detecting the 14 N NQR signal of urotropine C 6 H 1 N 4 with this coil are presented.

Design of a radio-frequency transceiver coil for landmine detection in Colombia by nuclear quadrupole resonance

“…An exception is the work of Farantatos et al [6], who made an electromagnetic design of a spiral coil in COMSOL Multiphysics for landmine detection; however, they did not considered noise as an important parameter in the design. Other works that deal with NQR coil design, not directly related to landmine detection, include: [7], which compares two-spiral flat coils having uniform and logarithmic windings for detecting NQR signals; and [8], which proposes a simulation method to estimate the detection efficiency of NQR. However, the specific characteristics of the target to be detected, like the size and shape of the enclosure and its depth, were not considered on these works.…”

Study of Relationship between NQR Signal Amplitudes and Nitrogen Contents in Explosive Simulants

“…Many countries are committed to the exploration and research on new methods and technology for the explosive detection. Nuclear quadrupole resonance (NQR) detection technology is deeply favored for its many advantages, such as high accuracy rate, low false alarm rate, non-magnetic pollution and so on [1][2][3][4]. However, the NQR frequencies of explosives are very low, usually in the range 0.5-6MHz, and the signal intensity is extremely weak.…”