Magnetic Source Imaging Using a Pulsed Optically Pumped Magnetometer Array

IEEE Trans Instrum Meas. 2019 Feb;68(2):493-501. doi: 10.1109/TIM.2018.2851458. Epub 2018 Jul 23.

Abstract

We have developed a pulsed optically pumped magnetometer (OPM) array for detecting magnetic field maps originated from an arbitrary current distribution. The presented magnetic source imaging (MSI) system features 24 OPM channels, has a data rate of 500 S/s, a sensitivity of 0.8 p T / H z , and a dynamic range of 72 dB. We have employed our pulsed- OPM MSI system for measuring the magnetic field map of a test coil structure. The coils are moved across the array in an indexed fashion to measure the magnetic field over an area larger than the array. The captured magnetic field maps show excellent agreement with the simulation results. Assuming a 2D current distribution, we have solved the inverse problem, using the measured magnetic field maps, and the reconstructed current distribution image is compared to that of the simulation.

Keywords: OPM; SERF; current distribution imaging; magnetic field map; magnetic source imaging; magnetometer.