A Wearable Wireless Magnetic Eye-Tracker, In-Vitro and In-Vivo Tests.

A wireless, wearable magnetic eye tracker is described and characterized. The proposed instrumentation enables simultaneous evaluation of eye and head angular displacements. Such a system can be used to determine the absolute gaze direction as well as to analyze spontaneous eye re-orientation in response to stimuli consisting in head rotations.

An innovative eye-tracker: Main features and demonstrative tests.

We present a set of results obtained with an innovative eye-tracker based on magnetic dipole localization by means of an array of magnetoresistive sensors. The system tracks both head and eye movements with a high rate (100-200 Sa/s) and in real time. A simple setup is arranged to simulate head and eye motions and to test the tracker performance under realistic conditions.

Fast switching coil system for sample premagnetization in an unshielded ultra-low-field nuclear magnetic resonance experiment.

We present a system developed to premagnetize liquid samples in an ultra-low-field nuclear magnetic resonance experiment. Liquid samples of a few milliliters are exposed to a magnetic field of about 70 mT, which is abruptly switched off, to leave a transverse microtesla field, where nuclei start precessing. An accurate characterization of the transients and intermediate field level enables a reliable operation of the detection system, which is based on an optical magnetometer.

Spurious ferromagnetic remanence detected by hybrid magnetometer.

Nuclear magnetic resonance detection in ultra-low-field regime enables the measurement of different components of a spurious remanence in the polymeric material constituting the sample container. A differential atomic magnetometer detects simultaneously the static field generated by the container and the time-dependent signal from the precessing nuclei. The nuclear precession responds with frequency shifts and decay rate variations to the container magnetization.

Enhanced Atomic Desorption of 209 and 210 Francium from Organic Coating.

Controlled atomic desorption from organic Poly-DiMethylSiloxane coating is demonstrated for improving the loading efficiency of Fr magneto-optical traps. A three times increase in the cold atoms population is obtained with contact-less pulsed light-induced desorption, applied to different isotopes, either bosonic or fermionic, of Francium. A six times increase of Fr population is obtained with a desorption mechanism based on direct charge transfer from a triboelectric probe to the adatom-organic coating complex.

A low noise modular current source for stable magnetic field control.

A low cost, stable, programmable, unipolar current source is described. The circuit is designed in view of a modular arrangement, suitable for applications where several DC sources must be controlled at once. A hybrid switching/linear design helps in improving the stability and in reducing the power dissipation and cross-talking.

Note: A fast pneumatic sample-shuttle with attenuated shocks.

We describe a home-built pneumatic shuttle suitable for the fast displacement of samples in the vicinity of a highly sensitive atomic magnetometer. The samples are magnetized at 1 T using a Halbach assembly of magnets. The device enables the remote detection of free-induction-decay in ultra-low-field and zero-field nuclear magnetic resonance (NMR) experiments, in relaxometric measurements and in other applications involving the displacement of magnetized samples within time intervals as short as a few tens of milliseconds.