Use of two or more sensors to detect different nuclear quadrupole resonance signals of a target compound

• US 7,355,401 B2
• Filed: 02/04/2005
• Issued: 04/08/2008
• Est. Priority Date: 02/04/2004
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Wilker, Charles, Laubacher, Daniel B., McCambridge, James D.
• Primary Examiner(s): Arana; Louis M.
• Application Number:
  US11/051,786
• Publication Number:
  US 20050206382A1
• Time in Patent Office: 1,159 Days
• Field of Search: 324/311, 324/300, 324/307, 324/314
• US Class Current: 324/300
• CPC Class Codes: G01N 24/084 Detection of potentially hazardous samples, e.g. toxic samples, explosives, drugs, firearms, weapons
• CPC Class Codes: G01R 33/441 Nuclear Quadrupole Resonance [NQR] Spectroscopy and Imaging

Abstract

The use of two or more sensors tuned to at least two different nuclear quadrupole resonance frequencies of a target compound to detect the different nuclear quadrupole resonance signals greatly reduces the chance of misidentification, and thereby improves nuclear quadrupole resonance detection system performance.

Claims

1. A method of detecting nuclear quadrupole resonance in a target compound comprising the steps of:

(a) applying a radio frequency magnetic field to the target compound using only one shielded-loop resonator coil thereby to produce at least two different nuclear quadrupole resonance signals from the target compound; and

(b) providing two or more high temperature superconductor self-resonant planar coil sensors, each sensor being operative solely to detect nuclear quadrupole resonance signals, each sensor being tuned to a different nuclear quadrupole resonance frequency of the target compound to detect the different nuclear quadrupole resonance signals thereof.

2. The method of claim 1 wherein the high temperature superconductor self-resonant planar coil sensors are YBa₂Cu₃O₇ or TI₂Ba₂CaCu₂O₈ self-resonant planar coils, and wherein the shielded-loop resonator coil is a copper shielded-loop resonator coil.

5. The method of claim 1 or 3 wherein the target compound comprises explosives, drugs or other contraband.

3. A method of detecting nuclear quadrupole resonance in a target compound comprising the steps of:

(a) applying a radio frequency magnetic field to the target compound using only one shielded-loop resonator coil thereby to produce at least M different nuclear quadrupole resonance signals from the target compound; and

(b) providing N high temperature superconductor self-resonant planar coil sensors, each sensor being operative solely to detect nuclear quadrupole resonance signals, each sensor being tuned to one of the M different nuclear quadrupole resonance frequencies of the target compound to detect the M different nuclear quadrupole resonance signals thereof, wherein N≧

2 and 2≦

M≦

N.

4. The method of claim 3, wherein the high temperature superconductor self-resonant planar coil sensors are YBa₂Cu₃O₇ or TI₂Ba₂CaCu₂O₈ self-resonant planar coils, and wherein the shielded-loop resonator coil is a copper shielded-loop resonator coil.

6. A nuclear quadrupole resonance detection system comprising:

a single shielded-loop resonator coil operative to produce at least two different nuclear quadrupole resonance signals from a target compound; and

two or more high temperature superconductor self-resonant planar coil sensors, each sensor being operative solely to detect nuclear quadrupole resonance signals, each of the sensors being tuned to a different nuclear quadrupole resonance frequency of the target compound, wherein each of the sensors detects a different nuclear quadrupole resonance signal characteristic of the target compound.

7. The nuclear quadrupole resonance detection system of claim 6 wherein the high temperature superconductor self-resonant planar coil sensors are YBa₂Cu₃O₇ or TI₂Ba₂CaCu₂O₈ self-resonant planar coils, and wherein the shielded-loop resonator coil is a copper shielded-loop resonator coil.

10. The nuclear quadrupole resonance detection system of claim 6 or 8 wherein the target compound comprises explosives, drugs or other contraband.

8. A nuclear quadrupole resonance detection system, comprising:

a single shielded-loop resonator coil operative to produce at least M different nuclear quadrupole resonance signals from a target compound; and

N high temperature superconductor self-resonant planar coil sensors each being operative solely to detect nuclear quadrupole resonance signals, each of the sensors being tuned to a different nuclear quadrupole resonance frequency of the target compound, wherein each of the N sensors detects a different one of the M different nuclear quadrupole resonance signals characteristic of the target compound, and wherein N≧

2 and 2≦

M≦

N.

9. The nuclear quadrupole resonance detection system of claim 8 wherein the high temperature superconductor self-resonant planar coil sensors are YBa₂Cu₃O₇ or TI₂Ba₂CaCu₂O₈ self-resonant planar coils, and wherein the shielded-loop resonator coil is a copper shielded-loop resonator coil.