We describe a portable four-channel array of chip-scale atomic magnetometers in a flexible flying-lead configuration. These microfabricated, uncooled sensors with volumes below 1 cm 3 demonstrate sensitivities around 100 fT/Hz 1/2 and bandwidths of several hundred hertz. Performance limits are discussed, as the design is easily scalable to different sensor sizes and large arrays. Initial measur...

This article introduces the influence of laser’s spin projection noise on the sensitivity of Cs atom magnetometer and concludes that the theoretical value of the spin projection noise is about1.23fT·Hz under the optimization conditions of the atom steam chest, namely temperature as 105°C, volume as 0.0785cm and molecular density as 1.7×10 cm. Such research has provided us with the necessary bas...

We show that a single atomic magnetometer in a magnetically unshielded environment can be used to perform magnetic particle spectroscopy (MPS) and AC susceptometry (ACS) on liquid-suspended magnetic nanoparticles. We demonstrate methods allowing a simultaneous recording of M (H ) and dM /dH (H ) dependences of samples containing down to 1 μg of iron. Our results pave the way towards an atomic m...

We calculate the flux threading the pick-up coil of a square SQUID magnetometer in the presence of a current dipole source. The result reproduces that of a circle coil magnetometer calculated by Wikswo [1] with only small differences. However it has a simpler form so that it is possible to derive from it closed form expressions for the current dipole sensitivity and the spatial resolution. The ...

The authors report on a rubidium atomic magnetometer designed for use in a shielded environment. Operating in the spin-exchange relaxation-free regime, the magnetometer utilizes parametric modulation of the z-magnetic field to suppress noise associated with airflow through the oven and to simultaneously detect x- and y-field components, using a single probe beam, with minimal loss of sensitivit...

An in-package voltage-sensing integrated magnetometer for low frequency neural recording at room temperature is presented. The detection system consists of a voltage mode CMOS amplifier with an active biasing circuit and a Metglas/Polyvinylidene fluoride (PVDF)-based magnetoelectric (ME) unimorph sensor measuring 10 × 3 × 0.025 mm in volume, representing the smallest ME sensor volume reported t...

We recorded the vector magnetogastrogram (MGG) due to gastric electrical activity (GEA) in normal rabbits using a Superconducting QUantum Interference Device (SQUID) magnetometer and measured the degree of correlation of the MGG with 24 channels of serosal electrodes. The vector magnetometer allows us to non-invasively record three orthogonal magnetic field components and project the recorded m...

The Equator-S magnetometer is very sensitive and has a sampling rate of normally 128 Hz. The high sampling rate allows for the ®rst time ̄uxgate magnetometer measurements of ELF waves between the ion cyclotron and the lower hybrid frequencies in the equatorial dayside magnetosheath. The so-called lion roars, typically seen by the Equator-S magnetometer at the bottom of the magnetic troughs of m...

We present a method for on-orbit, attitudeindependent magnetometer calibration that includes the effect of time-varying bias due to electronics on-board a spacecraft. The calibration estimates magnetometer scale factors, mis-alignments, and constant as well as time-varying bias. Timevarying effects are mitigated by including spacecraft telemetry in the measurement model and estimating constant ...

We present a hybrid tri-axes magnetometer designed to measure weak magnetic fields in space from DC (direct current) up to a few kHz with a better sensitivity than fluxgate magnetometers at frequencies above a few Hz. This magnetometer combines a wire-wound ferromagnetic ribbon and a classical induction sensor. The nature of the wire-wound ferromagnetic ribbon sensor, giant magneto-impedance or...