J. -L. Schenker | Searcharxiv

arXiv2009

A room temperature 19-channel magnetic field mapping device for cardiac signals

We present a multichannel cardiac magnetic field imaging system built in Fribourg from optical double-resonance Cs vapor magnetometers. It consists of 25 individual sensors designed to record magnetic field maps of the beating human heart by simultaneous measurements on a grid of 19 points over the chest. The system is operated as an array of second order gradiometers using sophisticated digitally controlled feedback loops.

physics.ins-det↗

arXiv2004

A high-sensitivity laser-pumped $M_x$-magnetometer

We discuss the design and performance of a laser-pumped cesium vapor magnetometer in the $M_x$-configuration. The device will be implemented for the control and stabilization of fluctuating magnetic fields and gradients in a new experiment searching for a permanent electric dipole moment of the neutron. We have determined the intrinsic sensitivity of the device to be 21 fT with a 1 s integration time, limited by low frequency noise of the laser power. In the shot noise limit the magnetometer can reach a sensitivity of 7 fT with a 1 s integration time. We have used the device to study the magnetic field fluctuations in a three layer mu-metal shield for integration times in the range of 2-100 seconds. The lowest values of the fluctuations are traced back to the stability of the power supply used to generate the field.

physics.atom-ph↗