Affiliations: [a] Japan Atomic Energy Agency, Sector of Fast Reactor and Advanced Research and Development, Tsuruga-shi, Fukui, Japan
Correspondence:
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Corresponding author: Ovidiu Mihalache, Japan Atomic Energy Agency, Sector of Fast Reactor and Advanced Research and Development, 919-1279, 1 Shiraki, Tsuruga-shi, Fukui, Japan. Tel.: +81 (0) 770 39 1031; Fax: +81 (0) 770 39 9114; E-mail: [email protected]
Abstract: The paper presents a fast and accurate algorithm to reconstruct the magnetization model of parallelepiped magnet (parts of a Halbach magnet array) or the Halbach magnet array used in an electromagnetic acoustic (EMAT) transducer. The model accuracy is validated against measurements of the magnetic flux distributions above surface of block magnets or Halbach magnet array using 2D/3D theoretical formula to compute magnetic flux distribution, validated by 2D/3D FEM simulations, and based on a non-uniform distribution of reconstructed magnetization model (using only main magnetization component). The illness of inverse reconstruction model is controlled through very small enough increments steps in an adaptive iterative algorithm but large enough increments to assure faster reconstruction, and converging to the same magnetization model of magnet blocks or Halbach array magnet, independent of the initial magnetization values.
Keywords: EMAT, Halbach magnetization reconstruction, 3D finite element
