A magnetic resonance detection (MRD) system for and methods of detecting and classifying multiple chemical substances is disclosed. In one example, the presently disclosed MRD system is a nuclear quadrupole resonance (NQR) detection system that provides multi-frequency operation for substantially full coverage of the explosive NQR spectrum using a broadband transmit/receive (T/R) switch (or duplexer) and a single multi-frequency radio frequency (RF) transducer. More particularly, the MRD system provides a frequency-agile system that can operate over a wide band of frequencies or wavelengths. Further, a method of detecting and classifying various chemical substances is provided that includes pulse sequencing with “frequency hopping,” phase cycling for reducing or substantially eliminating background noise, and/or a process of mitigating amplitude modulation (AM) radio interference.

A method of using the transverse relaxation rate (R.sub.2) of solvent NMR signal to detect filling errors of an alum-containing product in real-time in-line during manufacturing, for example during a fill-finish unit operation. This technique can be used for quality control in vaccine manufacturing to ensure the delivery of the correct concentration of alum-containing product to the product container such as a vial or pre-filled syringe.

A nuclear magnetic resonance (NMR) system is configured to detect combinatorial signatures stemming from homonuclear and heteronuclear J-couplings. The system comprises a pre-polarization system, a detector, and NMR electronics, wherein the detector includes an NMR magnet with a magnetic field of strength between 300 mT and 10 μT.

A method of using the transverse relaxation rate (R.sub.2) of solvent NMR signal to detect filling errors of an alum-containing product in real-time in-line during manufacturing, for example during a fill-finish unit operation. This technique can be used for quality control in vaccine manufacturing to ensure the delivery of the correct concentration of alum-containing product to the product container such as a vial or pre-filled syringe.

Portable electronic devices may be inspected for the presence of explosives using a combination of nuclear quadrupole resonance (NQR) and explosive trace detection (ETD). NQR may be used to detect bulk or sheet explosives while the ETD may be used to detect minute quantities of explosive particulates. An alarm indication may be generated when either the NQR spectroscopy or the ETD detects an explosive material.

Explosives concealed within electronic devices, such as smartphones and tablet PCs, are detected using NQR spectroscopy. For example, a suspect electronic device can be placed inside a NQR scanner and be subject to interrogation electromagnetic radiation at varying frequencies. The electronic device is exposed to interrogation electromagnetic radiation at frequencies that correspond to chemical components of various explosives. In the event that an explosive chemical component is present inside the electronic device, irradiating the electronic device with interrogation electromagnetic radiation at the specific NQR frequency of that explosive chemical component will cause the explosive chemical component to emit feedback electromagnetic radiation at that frequency. Consequently, the NQR scanner can measure the feedback electromagnetic radiation and determine that the frequency of the feedback electromagnetic radiation indicates the presence of the explosive chemical component inside the electronic device.

An antenna system is provided comprising first, second, and third loop antennas, each antenna having a respective loop area and spaced apart from the other antennas. The first and third antennas are configured and driven to form a first independent balanced feed point that is substantially isolated from the second antenna, which is configured to be driven from a second balanced feed point. A sum of the first and second respective loop areas, at a sum port in operable communication with the first and second balanced feed points, is substantially equivalent to the third respective loop area. An automatic control system is configured to automatically and independently adjust, via the balanced feed points, at least one of amplitude and phase for at least one of the three loop antennas, to help to substantially maximize suppression of RFI for a sum of signals from the first and second balanced feed points.

An exemplary integrated nuclear quadrupole resonance-based detection system comprises a front-end device having a hand-held form factor, wherein the front-end device is configured to scan a sample in or near a sample coil using inbuild electronics and acquire a nuclear quadrupole resonance measurement. The system further includes a swappable sample coil that is attached to an opening at a face of the front-end device and is tuned to a resonant frequency of the sample; and a swappable impedance matching network that is attached to the opening at the face of the front-end device and is configured to tune the resonant frequency of the sample coil. The inbuild electronics comprises a wireless transfer module that is configured to communicate the acquired nuclear quadrupole resonance measurement with a back-end device of the integrated nuclear quadrupole resonance-based detection system. Other systems and methods are also provided.

A transmission line array is used for explosive/contraband detection using nuclear quadrupole resonance in which the array is driven in-phase with synchrony frequency-swept signals. Each of the balanced transmission lines is fed with a low power swept frequency source and stimulated emissions are picked out with a directional coupler. Location is provided using a cross grid array or a phase detector is used for each balanced line, with phase determining the distance to the sensed substance.

The present invention provides an MRI-based hazard screening system for detecting contaminating particles within or on the surface of an object, the system characterized by a. a sampling environment adapted for at least partially confining said object; said sampling environment is in fluid communication with at least one inlet and at least one fluid outlet; b. a fluid streamer for streaming a fluid, throughout said at least one inlet, towards said sampling environment where said fluid effectively interfaces said object; and further throughout said at least one outlet; c. an MRI device in fluid communication with said at least one outlet, adapted for providing an image of said particles streamed by said fluid thereby screening the presence of said particles within or on the surface of said object.