الفهرس Only 14 pages are availabe for public view
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Abstract
This thesis represents a study of the shielding effectiveness of single and multi-layer magnetic shells against static and quasi-static magnetic and electric fields. A systematic method is clearly developed for the determination of the shielding effectiveness for single and multi-layer cylindrical and spherical shells. In order to shield against high intensity magnetic fields we have to use multiple shells arrangements where high saturation magnetic metals faces the high density magnetic field without the necessity of having high permeability. This is followed by a low saturation high permeability magnetic materials . The possibility of using more than two layers is also considered in this thesis. For a multi-layer magnetic shield each layer is separated from the next one by an air or vacuum gap. The general solution satisfying the suitable boundary conditions is reported in matrix form which facilitated the determination of the shielding effectiveness induction. Some numerical examples for the determination of the shielding effectiveness for both cylindrical and spherical multi-layer shields were considered to test the mathematical derivations. A systematic method is clearly developed for the solution of shielding effectiveness problems for multi-layer cylindrical and spherical metallic shells not in contact. In order to shield against high quasi-static electric field we have to use nonmagnetic conducting multi-layer shields of small thickness. The possibility of using more than two layers is also considered. In multi¬layer shielding against the electric field it is preferred to use air or vacuum gap between layers.
The arrangement of this thesis is as follows;
The first chapter gives a brief introduction to the idea of electromagnetic compatibility. The second gives some physical ideas about shielding theory. The third demonstrates a new solution for both cylindrical and spherical shielding problems against static magnetic field. The fourth one demonstrates new solutions for both cylindrical and spherical shielding problems against static magnetic fields. The fourth chapter deals with the same previous problems but with electrostatic fields. The conclusion and future work are in chapter five. The last part is for references and Arabic summary.