Performances and place of magnetometers based on amorphous wires compared to conventional magnetometers

Abstract We discuss and compare performances of various room temperature magnetometers. The work is directed towards the search of those magnetometers having a high sensitivity (>1000 V/T), a very low noise level (>1 pT/√Hz at white noise) attainable in a volume typically smaller than 1 cm3. The choice of this set of parameters is related to the useful comparison of room temperature magnetometers versus cryogenic ones, such as Superconducting Quantum Interferometer Devices (SQUIDs). The latter have highly degraded performances when their working operations needs an open unshielded environment as required for example in industrial application (non-destructive evaluation). SQUIDs have also a rather poor spatial resolution, and could be replaced by room temperature sensors in some magnetic imaging systems, which require a high spatial resolution. The paper is “highlighted” in the field of magnetic sensors based on amorphous magnetic wires that were used to carry out wide bandwidth (>100 kHz), very low noise flux gate (≈pT/√Hz at white noise) and highly sensitive, low noise magnetometers (≈pT/√Hz at white noise) Colpitts oscillator configuration use by K. Bushida's.