APPLICATIONS OF TECHNOLOGY:

• Detection of weak magnetic fields
• Nuclear magnetic resonance/nuclear quadrupole resonance (NMR/NQR)
• Compact, portable atomic magnetometers
• Narcotics and explosives detection
• Chemical analysis

ADVANTAGES:

• Resonance frequency is tunable
• Portability
• Simplified optical access, setup and operation
• Instrument's own magnetic field is suppressed
• Increased precision of measurement and improved signal-to-noise ratio

ABSTRACT:

Micah Ledbetter, Dmitry Budker, and Alexander Pines of the Berkeley Lab and UC Berkeley have devised a method of using an atomic magnetometer to detect weak radio frequency (RF) magnetic fields that offers greater portability and ease of operation than other magnetometers or pickup coils.

Typically, nuclear magnetic resonance (NMR) is detected either with an inductive pickup coil in a large magnetic field, requiring large, immobile magnets, or, more recently, by SQUID (superconducting quantum interference device) magnetometers, which require energy-intensive cryogenic cooling. The new method is based on nonlinear magneto-optical rotation (NMOR), which allows the resonance frequency of a RF atomic magnetometer to be adjusted to any desired value.

The new method allows measurements of the magnetic flux from a polarized nuclear sample to be taken at much lower magnetic fields. The temperature at which measurements can be taken (about 50 ° C) and the relatively low light power needed aids portability in situations where power is limited. Insulation around the magnetometer is reduced, making possible closer access to the sample, and the need for only a single laser beam makes setup and operation easier.

Because the magnetometer operates on alignment (quadrupole moment) rather than orientation (dipole moment), interference from the instrument's own magnetic field is greatly reduced, cutting down on problematic NMR frequency shifts. A further application is the detection of nuclear quadrupole resonance (NQR).

STATUS:

• Published PCT Patent Application WO2009/079054 available at www.wipo.int. Available for licensing or collaborative research.

To learn more about licensing a technology from LBNL see http://www.lbl.gov/Tech-Transfer/licensing/index.html.

FOR MORE INFORMATION:

M. P. Ledbetter, V. M. Acosta, S. M. Rochester, D. Budker, S. Pustelny, V. V. Yashchuk, "Detection of radio frequency magnetic fields using nonlinear magneto-optical rotation," Phys. Rev. A 2007, 75(2), 023405.

Dmitry Budker, Michael Romalis, "Optical Magnetometry," Nat. Phys . 2007, 3, 227.

REFERENCE NUMBER: IB-2482

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• Optical Atomic Magnetometer for Portable, Inexpensive MRI and Magnetic Microparticle Detection, IB-2232
• SQUID-Detected NMR and MRI and Ultralow Magnetic Fields, IB-1729
• Using Pulse Sequences to Achieve High Resolution NMR/MRI with Simplified Hardware, IB-2026
• Low-Field NMR/MRI Using Rotating-Frame Gradient Fields, IB-2288