First Characterization of the Ultra-Shielded Chamber in the Low-noise Underground Laboratory (LSBB) of Rustrel Pays d'Apt

In compliance with international agreements on nuclear weapons limitation, the French ground-based nuclear arsenal has been decommissioned in its totality. One of its former underground missile control centers, located in Rustrel, 60 km east of Avignon (Provence) has been converted into the ``Laboratoire Souterrain \`a Bas Bruit de Rustrel-Pays d'Apt'' (LSBB). The deepest experimental hall (500 m of calcite rock overburden) includes a 100 m$^{2}$ area of sturdy flooring suspended by and resting on shock absorbers, entirely enclosed in a 28 m-long, 8 m-diameter, 1 cm-thick steel Faraday cage. This results in an unparalleled combination of shielding against cosmic rays, acoustic, seismic and electromagnetic noise, which can be exploited for rare event searches using ultra low-temperature and superconducting detectors. The first characterization measurements in this unique civilian site are reported. For more info see http://home.cern.ch/collar/RUSTREL/rustrel.htmlComment: Homepage and quoted hyperlinks have been updated: see http://home.cern.ch/collar/RUSTREL/rustrel.htm

Magnetic properties of Co-Fe-Si-B microwires

In the paper the magneto-impedance effect in the Co68:15Fe4:35Si12:55B15 microwire with diameter of about 100 m is carefully studied. The measurements in close contact and contactless geometry were carried out in the static field ranging from 0 to 6 kA/m and frequencies of the alternating field from 20 Hz to 2 MHz. It is shown that the examined microwire shows high anisotropy of soft magnetic properties i.e. the circumferential permeability is at least 7 times higher than the longitudinal one. Moreover, the microwire can be used as highly sensitive magneto-impedance sensor working in contactless geometry especially at fields below 200 A/m[…

Aluminum Alloy Sensitization Evaluation by Using Eddy Current Techniques Based on IGMR-Magnetometer Head

International audienc

Offset Reduction in GMI-Based Device by Using Double-Frequency Bias-Current Modulation

International audienceIn this paper, we investigate the effect of temperature variations on the off-diagonal giant magneto-impedance (GMI) response. This paper is based on a theoretical model describing the GMI-based sensor response. The modeling has been extended to include the resistivity dependence versus the temperature. It allows to calculate both temperature sensitivity and intrinsic magnetic field sensitivity, whose ratio leads to the determination of the magnetic field offset drift versus the temperature. Thanks to an original conditioning circuitry based on a double ac current excitation instead of the classical one, we achieved an improvement of the long-term stability and minimized the sensor temperature dependence. Experimentally obtained results have been compared with the expected offset drift for the classical GMI, and with the expected fluctuation reduction while adopting this technique, showing a relatively good agreement with the proposed modeling