| 摘要 |
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. A potassium radio-frequency magnetometer with sensitivity of 0.24 fT/Hz1/2 operating at 423 kHz is provided. The magnetometer detected a 14N NQR signal from room temperature ammonium nitrate (NH4NO3) in the zero-applied field limit. Results demonstrate first time detection of NQR with an atomic magnetometer, providing that a cryogen-free atomic magnetometer, with intrinsically frequency-independent sensitivity and easy tuning capabilities, can be an attractive new tool for detecting magnetic resonance signals in the kHz to MHz range. Low intensity magnetic fields are 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.
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