High-Performance Recuperators for Low-Temperature Turbo-Brayton Cryocoolers

Future astrophysics missions require efficient, low-temperature cryocoolers to cool advanced instruments or to serve as the upper-stage cooler for sub-Kelvin refrigerators. Potential astrophysics missions include Lynx, the Origin Space Telescope, and the Superconducting Gravity Gradiometer. Cooling loads for these missions are up to 300 mW at temperatures of 4 to 10 K, with additional loads at higher temperatures for other subsystems. Due to low jitter requirements, a cryocooler with very low vibration is needed for many missions. In addition, a multistage cooler capable of providing refrigeration at more than one temperature simultaneously can provide the greatest system efficiency with the lowest mass. Turbo-Brayton cryocoolers have space heritage and are ideal for these missions due to negligible vibration emittance and high efficiency at low temperatures. The overall size, mass, and performance of Brayton cryocoolers are highly dependent on the technology employed in the recuperative heat exchangers (e.g.,nbsp;recuperators). On the proposed program, Creare plans to develop an advanced compact, lightweight recuperator focused on the low temperature range of the Brayton cryocooler. In Phasenbsp;I, we will perform design assessments, fabrication trials, and demonstration testing. In Phasenbsp;II, we will build and demonstrate an advanced recuperator for cryocoolers operating at temperatures down to 4 to 10nbsp;K.