EAGER: CRYO: Sub-Kelvin Refrigerator using a Superfluid Helium Vortex Cooling Principle

EARLY概念探索性研究资助（EAGER）支持基于新的两级冷却方法设计的新型冰箱的开发，达到1 K。 物理学家需要这个温度范围来证明新的量子现象，材料科学家需要发现新形式的材料，天文学家需要开发极其灵敏的探测器。随着新量子计算机的出现，对低于1 K温度的需求增加，目前在这些温度范围内运行。目前用于这种冷却的技术依赖于氦的稀有同位素（氦-3）作为制冷流体的必要组分以达到该温度。全球范围内的氦储备正在枯竭，需要新技术来满足1 K以下冷却和制冷的新需求，而不使用减少的He-3气体。该补助金还培训学生在这一重要领域增加劳动力。超流涡旋冷却器（SVC）和焦耳-汤普森预冷器的组合进行了研究，以实现高容量的亚开尔文冷却，而无需在系统中使用He-3。整个系统是零氦蒸发的封闭循环。受益于超流氦-4的喷泉泵效应，超流涡旋冷却器不需要任何移动部件或外部泵，结构紧凑，可以方便地连接到各种类型的预冷级，达到2K以下的温度以进行散热。完整的系统将是紧凑的，并在0.9K下提供显著的冷却能力（1 mW），理论冷却极限为0.65K。 本研究计划将根据能量传递的热分析来分析和设计系统。该计划将建立一个原型冷却器和基准的性能与估计。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

This EArly-concept Grant for Exploratory Research (EAGER) supports the development of a new type of refrigerators that reaches 1K based on the design of new two-stage cooling approaches. This temperature range is needed for physicalists to demonstrate novel quantum phenomena, for materials scientists to discover new form of materials, and for astronomers to develop extremely sensitive detectors. The need for sub-1K temperatures has been increased with the advent of new quantum computers, currently operating in these temperature ranges. Current technology for such cooling relies on a rare isotope of helium (Helium-3) as a necessary component of the refrigeration fluid to reach this temperature. The stockpile of helium is depleting worldwide, and new technologies are needed to meet the new demand for cooling and refrigeration below 1K without the use of diminishing He-3 gases. This grant also trains students in this important area increasing the workforce.The combination of a superfluid vortex cooler (SVC) and a Joule-Thompson precooler is researched to achieve high-capacity sub-kelvin cooling without the use of He-3 in the system. The complete system is closed cycle with zero helium boiloff. Benefiting from the fountain-pump effect of superfluid helium-4, the superfluid vortex cooler does not require any moving parts or an external pump, is compact, and can be conveniently attached to various types of precooling stages that reach a temperature below 2K for heat rejection. The complete system would be compact and provide significant cooling capacity ( 1mW) at 0.9K, with a theoretical cooling limit of 0.65K. This research program will analyze and design the system based on a thermal analysis of the energy transfer. The program will build a prototype cooler and benchmark the performance against estimates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.