Superconducting Directed Field Electromagnet for Magneto-Optics
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
A problem in magneto-optic recording is the application of a biasing magnetic field to the writing laser spot on the recording media at rates high enough to accomplish overwrite, thus avoiding an extra erase pass. Usually, the switching of the magnetic bias field is limited by the large inductance of the electromagnet. High switching rates of the bias field could be achieved if a superconducting open torus was used to contain and direct the bias field. One such configuration is shown in the figure for application to a disk-shaped recording media. The torus 1 contains a single loop of superconducting wire 2 placed next to the inside the torus but separated from it by a thin insulating layer to prevent shorting and Josephson effects.