Bubble domain technology for spacecraft onboard memory

Abstract

Bubble device technologies for spacecraft onboard memory offer improved reliability and memory functional characteristics. Recent advances include Permalloy gap devices (commercially available) whose improved performance and higher density are attributable to an asymmetric chevron pattern. Secondly, an order of magnitude increase in density at less power than the Permalloy technology is possible with the ion implant technology. A third technology, the self-structured current access system, offers another order of magnitude improvement in density and data rate, and is being studied. Capacity estimates for Permalloy gap, ion implant, and self-structured current access systems are, respectively, 10 to the 8th, 10 to the 9th, and 10 to the 10th bits, and power per unit data rate efficiencies are 140, 60, and 2 W/Mbps. A flexible modular organization system, compatible with all of these device technologies, is analyzed, and, as the system is contained in a bubble, relatively simple retrofitting is foreseen.