An unshielded radio-frequency atomic magnetometer with sub-femtoTesla sensitivity




Keder, David A.
Prescott, David W.
Conovaloff, Adam W.
Sauer, Karen L.

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AIP Publishing LLC


We demonstrate a radio-frequency potassium-vapor magnetometer operating with sensitivities of 0.3 fT/√Hz at 0.5 MHz and 0.9 fT/ √Hz at 1.31 MHz in the absence of radio-frequency and mu-metal or magnetic shielding. The use of spatially separated magnetometers, two voxels within the same cell, permits for the subtraction of common mode noise and the retention of a gradient signal, as from a local source. At 0.5 MHz the common mode noise was white and measured to be 3.4 fT/ √Hz; upon subtraction the noise returned to the values observed when the magnetometer was shielded. At 1.31 MHz, the common mode noise was from a nearby radio station and was reduced by a factor of 33 upon subtraction, limited only by the radio signal picked up by receiver electronics. Potential applications include in-the-field low-field magnetic resonance, such as the use of nuclear quadrupole resonance for the detection of explosives.



Calibration, Environmental noise, Magnetic resonance, Static magnetic fields, Coils


Keder, David A., David W. Prescott, Adam W. Conovaloff, and Karen L. Sauer. “An Unshielded Radio-Frequency Atomic Magnetometer with Sub-femtoTesla Sensitivity.” AIP Advances 4, no. 12 (December 1, 2014): 127159. doi:10.1063/1.4905449.