A miniaturized NQR spectrometer for a multi-channel NQR-based detection device

Area of Science:

• Nuclear Quadrupole Resonance (NQR) Spectroscopy
• Analytical Chemistry
• Portable Instrumentation

Background:

• Nuclear Quadrupole Resonance (NQR) is a sensitive technique for material identification.
• Existing NQR systems are often bulky and not portable.
• Detection of nitrogen-14 (14N) signals is crucial for identifying various compounds, including illicit materials.

Purpose of the Study:

• To design and assemble a sensitive, low-frequency, battery-operated pulsed NQR spectrometer.
• To achieve a portable NQR device with a total mass of approximately 3 kg.
• To demonstrate the capability of detecting (14)N NQR signals for material identification.

Main Methods:

• A pulsed NQR spectrometer operating at low frequencies (0.5-5 MHz) with up to 5 W transmitter power was constructed.
• A standard software-defined radio (SDR) platform was utilized for the data acquisition unit.
• Signal processing was performed using LabView Virtual Instrument on a personal computer.

Main Results:

• The spectrometer successfully detected (14)N NQR signals from reference materials.
• Tested compounds included aminotetrazole monohydrate (ATMH), potassium nitrate (PN), paracetamol (PCM), and trinitrotoluene (TNT).
• The designed spectrometer achieved a sensitive detection of (14)N NQR signals.

Conclusions:

• The developed low-frequency, portable NQR spectrometer is a feasible component for detection devices.
• This technology enables single or multichannel (14)N NQR based portable detection systems.
• The spectrometer's design facilitates the detection of (14)N NQR signals from various materials, including explosives and pharmaceuticals.