AC-susceptometry of magnetic nanoparticles using an atomic RF magnetometer

Existing Magnetic Particle Imaging (MPI) instruments detect the oscillating magnetic field produced by harmonically-excited magnetic nanoparticles (MNPs) with receive coils that pick up magnetic flux changes [1]. The direct measurement of MNP-produced magnetic flux was recently demonstrated [2] using fluxgate magnetometers as magnetic field sensors. Here we present an alternative approach to AC magnetic field sensing based on a laser-pumped atomic magnetometer operated as an rf field detector (atomic rf magnetometer, ARFM). We have developed an ARFM prototype and deploy it as field sensor in an AC magnetic susceptometer. Here we report on its current performance.