AbstractThe present invention provides a high sensitivity atomic magnetometer and methods of measuring low intensity magnetic fields that relate to the use of an alkali metal vapor and a buffer gas; increasing the magnetic polarization of the alkali metal vapor thereby increasing the sensitivity of the alkali metal vapor to a low intensity magnetic field; probing the magnetic polarization of the alkali metal vapor, the probing means providing an output from the alkali metal vapor, the output including characteristics related to the low intensity magnetic field; and measuring means that receives the output, determines the characteristics of the low intensity magnetic field, and provides a representation of the low intensity magnetic field. In addition, the invention relates to a magnetometer and methods that provide a representation of a first magnetic field originating within a sample volume. The sample volume may be part or all of a subject, such as a human subject. The representation includes a representation of a source of a magnetic field occurring within the sample volume displayed in one, two, or three of three orthogonal Cartesian coordinates, referenced to the sample volume. Other References- ---, SQUID Sensors: Fundamentals, Fabrication and Applications, Ed. Weinstock, H., Kluwer Academic (1996) (Abstract only).
- Affolderbach, C., et al., An all-optical, high sensitivity magnetic gradiometer, Appl Phys (2002) B 75: 605-612.
- Alexandrov, E.B. et al., Double-Resonance Atomic Magnetometers: from Gas Discharge to Laser Pumping, Laser Phys. (1996) 6: 244-251.
- Aleksandrov, E.B., et al. Laser pumping in the scheme of an Mx-magnetometer, Optics and Spectr. (1995) 78:292-298.
- Allred, J.C., et al., High-sensitivity atomic magnetometer unaffected by spin-exchange relaxation, Phys. Rev. Lett. (2002) 89:130801-1-130801-4.
- Bison, G., et al., A laser-pumped magnetometer for the mapping of human cardiomagnetic fields, Appl. Phys. B. (2003) 76:325-328.
- Bison, G., et al., Dynamical mapping of the human cardiomagnetic field with a room-temperature, laser-optical sensor, Opt. Expr. (2003) 11:904-909.
- Budker, D., et al., Resonant nonlinear magneto-optical effects in atoms, Rev. Mod. Phys. (2002) 74:1153-1201.
- Budker, D. et al., Nonliner Magneto-optic Effects with Ultranarrow Widths, Phys. Rev. Lett. (1998) 81:5788-5791.
- Budker, D., et al., Sensitive magnetometry based on non-linear magneto-optical rotation, Phys. Rev. A (2000) 62:043403-1-043403-7.
- Clem, T.R., Superconducting Magnetic Gradiometers For Underwater Target Detection, Nav. Eng. J. (1998) 110:139-149.
- Del Gratta C, et al., Magnetoencephalography—a noninvasive brain imaging method with 1 ms time resolution, Rep. Prog. Phys. (2001) 64:1759-1814.
- Drung, D., et al., Improved direct-coupled cd SQUID read-out electronics with automatic bias voltage tuning, IEEE T. Appl. Supercon. (2001) 11:880-883.
- Greenberg, Ya.S., Application of superconducting quantum interference devices to nuclear magnetic resonance, Rev. Mod. Phys. (1998) 70:175-222.
- Hämäläinen M. et al., Magnetoencephalography-theory, instrumentation, and applications to non-invasive studies on the working human brain, Rev. Mod. Phys. (1993) 65:413-497 (Abstract and contents only).
- Happer, W., Optical Pumping, Rev. Mod. Phys. 1972, 44:169-249 (Abstract and contents only).
- Happer, W., et al., Effect of rapid spin exchange on the magnetic-resonance spectrum of alkali vapors, Phys. Rev. A (1977) 16:1877-1991.
- Happer W. et al., Spin-Exchange Shift and Narrowing of Magnetic Resonane Lines inOptically Pumped Akali Vapors, Phys. Rev. Lett. (1973) 31:273-276.
- Harry, G.M., et al., Two-stage superconducting-quantum-interference-device amplifier in a high-Q gravitational wave transducer, Appl. Phys. Lett. (2000) 76:1446-1448.
- Kelha, V.O., et al., Design, Construction and Performance of a large-volume magnetic shield, IEEE Trans. Magn. (1982) 18:260-270.
- Kirschvink, J.L., et al., Paleomagnetic evidence of a low-temperature origin of carbonate in the Martian meteorite ALH84001, Science (1997) 275:1629-1633.
- Kominis, I. K. et al., A subfemtotesia multichannel atomic magnetometer, Nature (2003) 422:596-599.
- McDermott, R., et al., Liquid-state NMR and scalar couplings in microtesia magnetic fields, Science (2002) 295:2247-2249.
- Murthy, S. A., et al, New Limits on the Electron Electric Dipole Moment from Cesium, Phys. Rev. Lett. (1989) 63:965-968.
- Nenone, J., et al., Thermal noise in biomagnetic measurements, Rev. Sci. Instr. (1996) 67:2397-2405.
- Nenonen, J., et al., Thermal Noise in a Magnetically Shielded Room, in Biomagnetism '87 , Ed. K. Atsumi et al., Denki University Press, Tokyo, 1988), p. 426-429.
- Oukhanski, N., et al., Low-drift broadband directly coupled dc SQUID read-out electronics, Physica C (2002) 368:166-170.
- Rodriguez, E., et al., Perception's shadow: long-distance synchronization of human brain activity, Nature (1999) 397:430-433.
- Tralshawala, N., et al., Practical SQUID instrument for non-destructive testing, Appl. Phys. Lett. (1997) 71:1573-1575.
- Ts'o, D.Y., et al., Functional organisation of primate visual cortex revealed by high-resolution optical imaging, Science (1990) 249:417-420.
- Tsuei, C.C. et al., Phase-sensitive evidence for d-wave pairing symmetry in electron-doped cuprate superconductors, Phys. Rev. Lett. (2000) 85:182-185.
- Varpula, T., et al., J. App. Phys. (1984) 55:4015-4021.
- Zimmerman, J.E., et al., Design and operation of stable RF-biased superconducting point-contact quantum devices, and a note on properties of perfectly clean metal contacts. J. Appl. Phys. (1970) 41, 1572-1580.
| InventorsAssigneeApplication No. 10687012 filed on 10/16/2003 US Classes:324/304, Using optical pumping or sensing device324/301, Using a magnetometer250/251ELECTRICALLY NEUTRAL MOLECULAR OR ATOMIC BEAM DEVICES AND METHODSField of Search324/304, Using optical pumping or sensing device324/301, Using a magnetometer324/300, PARTICLE PRECESSION RESONANCE324/318, Spectrometer components324/322Electronic circuit elementsExaminers Primary: Arana, LouisAttorney, Agent or FirmUS Patent References4005355, Method and apparatus for stimulating narrow line resonance conditions Issued on: 01/25/1977 Inventor: Happer , et al.4525672, Apparatus and method for laser pumping of nuclear magnetic resonance cell Issued on: 06/25/1985 Inventor: Lam , et al.4617462, Polarized internal target apparatus Issued on: 10/14/1986 Inventor: Holt5189368Magnetometer Issued on: 02/23/1993 Inventor: ChaseInternational Class G01V 3/00
|