Improved Cryogenic Cooling Technology: Low Jitter, Low Mass on Gimbal

We propose an extension of our patented Flexibly-Attached Remote (FAR) acoustic-Stirling coldhead technology to multi-stage, multi-point cooling of gimbal-mounted electro-optical space payloads. Acoustic-Stirling (sometimes called Stirling ''pulse-tube'') is sealed, valveless, and oilless for extreme robustness. CFIC-Qdrive has developed means to practically separate the coldhead (zero moving parts) from the more massive (and vibrating) driver by up to 2 meters of flexible line, to one or more heads on a common driver, with little or no efficiency penalty. We have demonstrated 77K capacities in terrestrial FAR coolers sized from 10W to over 600W (3 parallel 200W heads). An experimental 2-stage head on our balanced twin-motor driver has reached 13K. In this proposal, we will simulate, design, and evaluate 2-stage FAR acoustic-Stirling coolers for both 2W@40K+20W@85K and 12W@110K+20W@170K; to determine the optimal configurations, evaluate the on-gimbal mass reduction and the total system mass; measure net vibration forces in present terrestrial implementations as a baseline for space versions; and produce recommendations for prototype development and measures of performance and residual jitter-causing vibrations, on selected sensor platform in Phase II. BENEFIT: Cooling with zero moving parts on gimbal; reduced jitter and on-gimbal mass; Higher cooling capacity (by adaptation of scalable Qdrive cooler architecture to space EO loads); Expanded applicability of reliable Qdrive FAR coolers to lower temperatures via 2-stage development (useful for MRI, HTS power, and SQUID instruments).