Magnetic Flip Flops for Space Applications

The radiation environment of space presents a significant threat to the reliability of nonvolatile memory technologies. Ionizing radiation disturbs the charge stored on floating gates, and cosmic rays can permanently damage thin oxides. A new memory technology based on the magnetic tunneling junction (MTJ) appears to offer superior resistance to radiation effects and virtually unlimited write endurance. A magnetic flip flop has a number of potential applications, such as the configuration memory in field-programmable logic devices. However, using MTJs in a flip flop requires radically different circuitry for storing and retrieving data. New techniques are needed to insure that magnetic flip flops are reliable in the radiation environment of space. We propose a new radiation-tolerant magnetic flip flop that uses the inherent resistance of the MTJ to increase its immunity to single event upset and employs a robust “Pac-man” magnetic element.

Kinora and Double Kinora (Mutoscope)

The mutoscope is a cylindrical container ranging in size from a large, standing viewing station down to a smaller, more transportable unit. These machines hold hundreds of small cards with images printed on them attached to a circular core. This core is attached to an external crank which is turned by the viewer. The booklet turns, and the cards are held tensely bent into viewing position by a small metal piece. As the cards flip by, the rapid frame rate produces the illusion of a moving image (Rossell,Living Pictures, 96).