Process for determining intrinsic magnetic permeability of elongated ferromagnetic elements and electromagnetic properties of composites using such elements
AssigneeCommissariat a l'Energie Atomique
InventorsOlivier Acher, Pierre Marie Jacquart, Alfred Schaal
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Abstract
A process for determining the intrinsic magnetic permeability of elongated ferromagnetic elements and the electromagnetic properties of composites using such elements are disclosed. According to the process, an annular core or torus is produced, which torus is wound with ferromagnetic elements. The core is placed in a coaxial line, the properties of the torus are measured, and permeability of the elements and the properties of an equivalent composite for a given polarization are deduced from such measurement. Particular utility is found in the area of study of composite charges for use at microwave frequencies.
Claims44
A process for determining intrinsic magnetic permeability of ferromagnetic elements having an elongated shape in at least one direction, comprising:
- winding the ferromagnetic elements to form a torus, said ferromagnetic elements being coated with an electrically insulating material, said ferromagnetic elements being longitudinally disposed in the torus in a substantially tangential direction relative to the torus,
- placing said torus in a coaxial line of a magnetic permeability measuring means for facilitating measurement of magnetic permeability (.mu.m) of said torus,
- measuring magnetic permeability (.mu.m) of the torus using said measuring means, and
- from the magnetic permeability (.mu.m) measured and ferromagnetic material fraction (F) determined to be contained in the torus deducing the intrinsic magnetic permeability (.mu.f) of said ferromagnetic elements.
A process for determining electromagnetic properties of permeability and permittivity for a given polarization of a composite comprising ferromagnetic elements having an elongated shape in at least one direction and an electrical insulator, all said ferromagnetic elements being oriented in an orientation direction in the composite, said process comprising:
- winding the ferromagnetic elements to form a torus, said ferromagnetic elements being coated with said electrical insulator, ferromagnetic element charge rate in the torus being equal to composite charge rate, said elements being longitudinally disposed in the torus in a substantially tangential direction relative to the torus,
- placing said torus in a coaxial line of a magnetic permeability (.mu.m) measuring means,
- determining the magnetic permeability (.mu.m) and the electrical permittivity (.epsilon.m) of the torus in the coaxial line using said measuring means, said magnetic permeability (.mu.m) and electrical permittivity (.epsilon.m) of the torus corresponding to said electromagnetic properties of the composite for a polarization corresponding to the electromagnetic conditions of the torus in the coaxial line.
Dependencies are inferred from the claim text.