Method and system for applying NQR pulse sequences

Patent metadata

Field	Value
Publication number	US-9927550-B2
Application number	US-201314383886-A
Country	US
Kind code	B2
Filing date	Mar 7, 2013
Priority date	Mar 8, 2012
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A method and system for applying nuclear quadrupole resonance (NQR) sequences to a substance and determining presence of a chemical species within the substance using the sequences are described herein. The method includes applying an NQR pulse sequence to the substance using a non-resonant transmitter circuit. The method further includes detecting a NQR signal within the substance and determining presence of a chemical species within the substance using the NQR signal.

First claim

We claim:

1. A method for determining presence of a chemical species within a substance using nuclear quadrupole resonance (NQR), the method comprising:
applying a first NQR pulse sequence to the substance using broadband electronics having a non-resonant transmitter circuit;
detecting a first NQR signal within the substance corresponding to said first NQR pulse sequence;
applying a plurality of NQR pulse sequences at a plurality of frequencies to the substance using said broadband electronics having said non-resonant transmitter circuit without adjusting said broadband electronics;
detecting a plurality of NQR signals within the substance corresponding to said plurality of NQR pulse sequences at said plurality of frequencies; and
determining presence of a chemical species within the substance using the first NQR signal and said plurality of NQR signals.

2. The method according to claim 1 , wherein the first NQR pulse sequence is applied at a first set of frequencies selected to match at least one known NQR frequency of a first set of atomic nuclei within the chemical species and the first NQR pulse sequence generates the first NQR signal.

3. The method according to claim 2 , wherein the first set of frequencies comprises a first frequency selected to match a first known NQR frequency of the first set of atomic nuclei within the chemical species and
the second NQR pulse sequence includes:
at least one pulse at the first frequency; and
a pulse sequence segment at a second frequency selected to match a second known NQR frequency of the first set of atomic nuclei within the chemical species, wherein the second pulse sequence segment generates a second NQR signal within the substance.

4. The method of claim 3 , wherein said determining the presence of the chemical species within the substance is determined by comparing the first NQR signal and the second NQR signal.

5. The method according to claim 4 , wherein an amplitude of the first NQR signal and an amplitude of the second NQR signal are compared to determine the presence of the chemical species within the substance.

6. The method according to claim 2 , further comprising:
applying a third NQR pulse sequence to the substance using said broadband electronics having the non-resonant transmitter circuit without adjusting said broadband electronics, wherein the third NQR pulse sequence is applied at a third set of frequencies selected to match at least one known NQR frequency of a second set of atomic nuclei within the chemical species and the third NQR pulse sequence generates a third NQR signal; and
detecting the third NQR signal.

7. The method of claim 6 , wherein the presence of the chemical species within the substance is determined using the first NQR signal and the third NQR signal.

8. The method of claim 7 , wherein the first set of atomic nuclei and the second set of atomic nuclei are different chemical elements.

9. The method of claim 7 , wherein the first set of atomic nuclei and the second set of atomic nuclei are the same chemical elements located at different sites within the chemical species.

10. The method according to claim 1 , wherein the chemical species is a chemical compound.

11. The method according to claim 2 , wherein the first set of atomic nuclei is selected from the group consisting of: nitrogen, chlorine and copper.

12. The method according to claim 2 , wherein the first set of atomic nuclei is nitrogen and the chemical species is selected from the group consisting of: Glycine, Ammonium Nitrate, TNT, RDX, Cocaine Hydrochloride, and Heroin Hydrochloride.

13. The method according to claim 7 , wherein the first set of atomic nuclei is nitrogen, the second set of atomic nuclei is chlorine, and the chemical species is selected from the group consisting of: Cocaine Hydrochloride and Heroin Hydrochloride.

14. The method according to claim 6 , wherein the third NQR pulse sequence is applied before the first set of atomic nuclei reach thermal equilibrium.

15. The method according to claim 14 , wherein the third NQR pulse sequence is interposed within the first NQR pulse sequence.

16. The method according to claim 2 , further comprising:
applying a plurality NQR pulse sequences at frequencies selected to match known NQR frequencies of a plurality of different atomic nuclei within the chemical species;
using a plurality of NQR signals from each of the plurality of different atomic nuclei to determine the presence of the chemical species.

17. A method for applying a nuclear quadrupole resonance (NQR) sequence to a substance, the method comprising:
applying an NQR pulse sequence to the substance using broadband electronics having a non-resonant transmitter circuit, the NQR pulse sequence comprising:
a first pulse sequence segment at a first frequency selected to match a first known NQR frequency of a first set of atomic nuclei; and
a second pulse sequence segment at a second frequency selected to match a second known NQR frequency of a second set of atomic nuclei, wherein the second pulse sequence segment is initiated before the first set of atomic nuclei reach thermal equilibrium, with said first pulse sequence and said second pulse sequence being applied without adjusting said broadband electronics.

18. The method according to claim 17 , wherein the second pulse sequence segment is at least partially interposed within the first pulse sequence segment.

19. The method according to claim 17 , wherein the NQR pulse sequence includes at least three pulse sequence segments that are applied at different frequencies and configured to generate NQR signals in three different sets of atomic nuclei and at least two of the pulse sequence segments are at least partially interposed within the first pulse sequence segment.

20. A system comprising:
a coil for applying a nuclear magnetic resonance (NQR) pulse sequences to a substance;
a NQR transmitter comprising a broadband electronics circuit including a non-resonant NQR transmitter circuit electronically coupled to the coil; and
a processor;
a memory storing instructions executable by the processor to perform processes that include providing NQR pulse sequences to the NQR transmitter without adjusting said broadband electronics, wherein the NQR pulse sequences comprise a first NQR pulse sequence comprising a first frequency selected to match a known NQR frequency of a first set of atomic nuclei within the chemical species, and
a second NQR pulse sequence comprising a second frequency selected to match a known NQR frequency of a second set of atomic nuclei within the chemical species.

21. The system according to claim 20 , further comprising:
a NQR receiver that is configured to receive NQR signals generated within the substance and detected at the coil.

22. The system according to claim 21 , wherein the processes further include determining presence of a chemical species within the substance using the NQR signals.

23. The system according to claim 20 , wherein the processes further include determining the presence of a chemical species within the substance using the NQR signals generated by the first NQR pulse sequence and the second NQR pulse sequence.

24. The system according to claim 20 , wherein the first NQR pulse sequence and the second NQR pulse sequence are interposed.

25. The system according to claim 22 , wherein the NQR pulse sequences comprise:
a first NQR pulse sequence comprising

Assignees

• Schlumberger Technology Corp

Inventors

• Mandal Soumyajit
• Song Yi-Qiao

Classifications

• G01N24/084 Primary

  Detection of potentially hazardous samples, e.g. toxic samples, explosives, drugs, firearms, weapons · CPC title

• G01N24/087

  Structure determination of a chemical compound, e.g. of a biomolecule such as a protein · CPC title

• G01V3/14

  operating with electron or nuclear magnetic resonance · CPC title

• G01R33/441 Primary

  Nuclear Quadrupole Resonance [NQR] Spectroscopy and Imaging · CPC title

• G01V3/32 Primary

  operating with electron or nuclear magnetic resonance · CPC title