Fundamental limits to magnetic-field sensitivity of flux-gate magnetic-field sensors

Citation
Rh. Koch et al., Fundamental limits to magnetic-field sensitivity of flux-gate magnetic-field sensors, APPL PHYS L, 75(24), 1999, pp. 3862-3864
Citations number
8
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
00036951 → ACNP
Volume
75
Issue
24
Year of publication
1999
Pages
3862 - 3864
Database
ISI
SICI code
0003-6951(199912)75:24<3862:FLTMSO>2.0.ZU;2-Y
Abstract
In this letter we determine the theoretical limit of the magnetic-field sen sitivity of the flux-gate magnetometer. In order to do so, we have develope d a model for the white noise of a flux gate based on the fundamental dynam ics of the magnetic material forming the flux-gate core. Solving this model , we predict that the white noise of a physically realizable flux gate with a volume of 2x10(-8) m(3) is less than 100 fT/root Hz. The white noise var ies with the lossy susceptibility of the core and inversely with the volume . We also compare the measured white noise of a thin-film flux gate with th e predictions of our model and find that the measured and predicted noise a gree reasonably well. (C) 1999 American Institute of Physics. [S0003-6951(9 9)03550-0].