AC vector magnetic anomaly detection with diamond nitrogen vacancies

Patent metadata

Field	Value
Publication number	US-10338162-B2
Application number	US-201615003670-A
Country	US
Kind code	B2
Filing date	Jan 21, 2016
Priority date	Jan 21, 2016
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

A system for magnetic anomaly detection is described. The system may include a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers. A controller modulates a first code packet and controls a first magnetic field generator to apply a first time varying magnetic field at the NV diamond material based on the modulated first code packet. The controller modulates a second code packet and control a second magnetic field generator to apply a second time varying magnetic field at the NV diamond material based on the modulated second code packet, wherein the first code packet and the second code packet are binary sequences which have a low cross correlation with each other. The controller determines a magnitude and direction of the magnetic field at the NV diamond material, and determines a magnetic vector anomaly based on the determined magnitude and direction of the magnetic field.

First claim

What is claimed is:

1. A system for magnetic detection, comprising:
a magneto-optical defect center material comprising a plurality of magneto-optical defect centers;
a magnetic field generator configured to generate a magnetic field;
a radio frequency (RF) excitation source configured to provide RF excitation to the magneto-optical defect center material;
an optical excitation source configured to provide optical excitation to the magneto-optical defect center material;
an optical detector configured to receive an optical signal emitted by the magneto-optical defect center material; and
a controller configured to:
control the magnetic field generator to apply a time varying magnetic field at the magneto-optical defect center material,
determine a magnitude and direction of the magnetic field at the magneto-optical defect center material based on a received light detection signal from the optical detector, and
determine a magnetic vector anomaly due to an object based on the determined magnitude and direction of the magnetic field according to a frequency dependent attenuation of the time varying magnetic field.

2. The system of claim 1 , wherein the object is ferrous.

3. The system of claim 1 , wherein the object is non-ferrous.

4. A system for magnetic detection, comprising:
a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers;
a magnetic field generator comprising at least two magnetic field generators including a first magnetic field generator configured to generate a first magnetic field and a second magnetic field generator configured to generate a second magnetic field;
a radio frequency (RF) excitation source configured to provide RF excitation to the NV diamond material;
an optical excitation source configured to provide optical excitation to the NV diamond material;
an optical detector configured to receive an optical signal emitted by the NV diamond material; and
a controller configured to:
modulate a first code packet and control the first magnetic field generator to apply a first time varying magnetic field at the NV diamond material based on the modulated first code packet,
modulate a second code packet and control the second magnetic field generator to apply a second time varying magnetic field at the NV diamond material based on the modulated second code packet, wherein the first code packet and the second code packet are binary sequences which have a low cross correlation with each other, and each of the binary sequences has a good autocorrelation.

5. The system of claim 4 , wherein a direction of the first time varying magnetic field at the NV diamond material is different from a direction of the second time varying magnetic field at the NV diamond material.

6. The system of claim 4 , wherein the controller is further configure to:
receive first light detection signals from the optical detector based on the optical signal emitted by the NV diamond material based on the first code packet transmitted to the NV diamond material, and receive second light detection signals from the optical detector based on the optical signal emitted by the NV diamond material based on the second code packet transmitted to the NV diamond material simultaneous with the first code packet being transmitted to the NV diamond material;
apply matched filters to the received first and second light detection signals to demodulate the first and second code packets,
determine a magnitude and direction of the first magnetic field and the second magnetic field at the NV diamond material based on the demodulated first and second code packets; and
determine a magnetic vector anomaly based on the determined magnitude and direction of the first magnetic field and the second magnetic field.

7. The system of claim 4 , wherein the first and second code packets are modulated by continuous phase modulation.

8. The system of claim 4 , wherein the first and second code packets are modulated by MSK frequency modulation.

9. A system for magnetic detection, comprising:
a magneto-optical defect center material comprising a plurality of magneto-optical defect centers;
a magnetic field generator configured to generate a magnetic field;
a radio frequency (RF) excitation source configured to provide RF excitation to the magneto-optical defect center material;
an optical excitation source configured to provide optical excitation to the magneto-optical defect center material;
an optical detector configured to receive an optical signal emitted by the magneto-optical defect center material; and
a controller configured to:
control the magnetic field generator to apply a time varying magnetic field at the magneto-optical defect center material,
determine a magnitude and direction of the magnetic field at the magneto-optical defect center material based on a received light detection signal from the optical detector, and
determine a magnetic vector anomaly based on the determined magnitude and direction of the magnetic field.

10. The system of claim 9 , wherein the magnetic field generator comprising two or more magnetic field generators including a first magnetic field generator configured to generate a first magnetic field at the magneto-optical defect center material in a first direction and a second magnetic field generator configured to generate a second magnetic field at the magneto-optical defect center material in a second direction different from the first direction.

11. The system of claim 10 , wherein the first direction is orthogonal to the second direction.

12. The system of claim 10 , wherein the controller is configured to:
modulate a first code packet and control the first magnetic field generator to apply a first time varying magnetic field at the magneto-optical defect center material based on the modulated first code packet, and
modulate a second code packet and control the second magnetic field generator to apply a second time varying magnetic field at the magneto-optical defect center material based on the modulated second code packet, wherein the first code packet and the second code packet are binary sequences which have a low cross correlation with each other, and each of the binary sequences has a good autocorrelation.

13. A system for magnetic detection, comprising:
a magneto-optical defect center material comprising a plurality of magneto-optical defect centers;
a magnetic field generator comprising two or more magnetic field generators including a first magnetic field generator configured to generate a first magnetic field and a second magnetic field generator configured to generate a second magnetic field;
a radio frequency (RF) excitation source configured to provide RF excitation to the magneto-optical defect center material;
an optical excitation source configured to provide optical excitation to the magneto-optical defect center material;
an optical detector configured to receive an optical signal emitted by the magneto-optical defect center material; and
a controller configured to:
control the first magnetic field generator to apply a first time varying magnetic field at the magneto-optical defect center material,
control the second magnetic field generator to apply a second time varying magnetic field at the magneto-optical defect center material, wherein a direction of the first time varying magnetic field at the magneto-optical defect center material is different from a direction of the second time varying magnetic field at the magneto-optical defect center material,
determine a magnitude and direction of the first magnetic field and the second magnetic field at the magneto-optical defec

Assignees

• Lockheed Corp

Inventors

• Reynolds Colleen Mary
• COAR David Nelson
• DECRISTOFORO Mary Catherine Chih-Li
• Egan Laird Nicholas
• Russo Jon C

Classifications

• G01R33/26 Primary

  using optical pumping · CPC title