Superconducting Digital Multiplexers for Sensor Arrays

Large arrays of cryogenic microbolometers and other cryogenic detectors will be used for infrared imaging in future space observatories. If the signal from the sensors is amplified, multiplexed, and digitized using superconducting electronics, then this data can be efficiently read out to room temperature with a minimum of noise and thermal load. HYPRES will develop an integrated system based on SQUID amplifiers, a high-resolution analog-to-digital converter (ADC) based on RSFQ (rapid single flux quantum) logic, and a clocked RSFQ multiplexer. The ADC and SQUIDs have already been developed for other projects, so this work will focus on demonstrating the perfomance of the digital multiplexer, starting with a 3x3 prototype for Phase I.