부산대학교 도서관

The magnetic field B induced along the axis of symmetry of axially magnetized cones was studied analytically and experimentally for various cone angles α. An explicit algebraic equation was derived for sharp-pointed and truncated cones. A sharp cone is characterized by singularities of B and ∇ B at its apex point. For a truncated cone, the maximum values of these quantities are achieved for α m a x ∼ 54.7 ° and α ∇ ∼ 39.2 ° , respectively. Two truncated cones with α u n i ∼ 63.4 ° positioned in a mirrored co-apex configuration produce a uniform axial field in the free-space gap. For smaller angles, the minimum field is located in the center of the airgap, while for larger, it is at the cones' surfaces with extremum at α m i n ∼ 71.6 °. These predictions were investigated using a tunable apparatus in which Co–Fe cones are magnetized by cylindrical NdFeB magnets. Strong ∼ 4 T B-field was achieved. Experimental results are discussed in detail, including incomplete magnetization and other secondary effects. [ABSTRACT FROM AUTHOR]