An improved mesh shaking coil and its application to a magnetic shielding panel

An improved structure for a mesh shaking coil with finite area is presented by which shielding performance of ferromagnetic shielding is enhanced while suppressing unwanted leakage of the shaking field. A surrounding conductor is added in series to a finite mesh coil in order to cancel the edge effect which deteriorates the multipole distribution of the shaking field. Cancellation of the edge effect is confirmed by experiment and calculation. The improved mesh coil is applied to develop a magnetic shielding panel with a magnetic sheet/coil/magnetic sheet sandwich structure. The shielding factor of a 20-cm/sup 2/ shielding panel of 6.5% Si-Fe steel was enhanced about three times to 152 by magnetic shaking using the mesh shaking coil.<>