Geophysical Centre in Dourbes

The magnetically shielded room (MSR) for low-field applications is intended for experiments in ambient fields smaller than 50 nT. These include magnetic field sensor calibration, various physical experiments, simulating interplanetary/interstellar magnetic field conditions, or the monitoring of bio-magnetic signals (e.g. magnetocardiography and magnetoencephalography).

The exterior shield consists of a double layer of electrical steel (2 x 1 mm thick) and has on all faces direct current (DC) coil windings (vertical and north-south horizontal) to impart an anhysteretic remanent magnetisation (ARM). The interior shield is made of a single mu-metal layer (1 mm thick) and is equipped with active DC coils to compensate small static and dynamic residual fields (and linear field gradients) . The low-field MSR has internal dimensions of 3.81 x 3.05 x 2.15 m (L, W, H) and is oriented in an east-west direction (length). It contains no cables or installations, except those necessary for field compensation. Electricity, data cables and lighting can be brought inside using mobile devices.