Researchers at Princeton University have developed a novel high sensitivity magnetometer having the ability to detect and measure very low magnetic field intensities. The device relies on polarizing alkali metal vapor, and probing the state of magnetization of the polarized metal atoms to measure characteristics of a magnetic field originating from a variety of sources.
The device is a radio-frequency tunable atomic magnetometer for detection of nuclear quadrupole resonance (NQR) from room temperature solids, including detection of nitrogen-containing explosives placed external to a sensor unit. The potassium radio-frequency magnetometer has a sensitivity of 0.24 fT/Hz.sup.1/2 operating at 423 kHz. The magnetometer can detect a .sup.14N NQR signal from room temperature ammonium nitrate (NH.sub.4NO.sub.3) in the zero-applied field limit. Results demonstrate, for the first time, detection of NQR with an atomic magnetometer, cryogen-free, with intrinsically frequency-independent sensitivity and easy tuning capabilities, that can be used for detecting magnetic resonance signals in the kHz to MHz range. Low intensity magnetic fields can be measured using an alkali metal vapor, by increasing magnetic polarization of the vapor to increase its sensitivity, then probing the magnetic polarization of the vapor to receive an output, and determining characteristics of the low intensity magnetic field from the output.
Patent protection has been granted under US # 7,521,928.
For more information please contact:
William H. Gowen
Office of Technology Licensing and Intellectual Property
Princeton University
4 New South Building
Princeton, NJ 08544-0036
(609) 258-6762
(609) 258-1159 fax
wgowen@princeton.edu