SBIR Phase I: A Revolutionary Design for a Continuous Adiabatic Demagnetization Refrigerator

这个小型企业创新研究(SBIR)第一阶段项目将通过建造和测试原型来证明新型连续绝热消磁冰箱(CADR)设计的可行性。这项新技术有可能大大降低超低温研究的成本。目前，如果研究人员需要将实验温度保持在0.1K以下几天以上，只有一种可行的技术：稀释冰箱。这些冰箱依赖非常稀有的同位素He-3(主要来自核储备中的氚衰变)，而且相当昂贵(350,000美元或更多)。将在第一阶段开发的技术承诺通过避免稀释式冰箱的复杂性、规模、基础设施要求和对He-3的依赖，大幅降低这一成本。设想的CADR有可能帮助实现经济高效的量子计算，广泛部署用于跟踪核材料的超灵敏探测器，创建对某些加密方案至关重要的量子信息传感器，以及其他迄今未知的结果。该项目的智力优势是创造了一种革命性的超低温冰箱。在第一阶段的工作中，将创建一台原型冰箱，以演示这一新设计的基本工作原理。这台原型冰箱将使用单级镓石榴石(GGG)作为制冷剂，将热量从亚开尔文温度持续提升到3K脉冲管。这台冰箱将作为第二阶段设计和测试的两级冰箱的概念验证。未来的两级冰箱将使用GGG预冷明矾铁铵(FAA)，以达到0.1开尔文及以下。这一阶段的研究工作将以子系统特性(热开关、磁屏蔽等)、设计、建造和测试的迭代过程为特色。第一阶段的工作重点是回答围绕CADR工程的可行性问题，同时将100MK温度、多级冷却和深入分析留到第二阶段。在第一阶段结束时将展示和表征的成功概念验证冰箱将把有用的热量(目标为0.5毫瓦)从亚开尔文温度转移到3K脉冲管。

This Small Business Innovation Research (SBIR) Phase I project will demonstrate the feasibility of a novel Continuous Adiabatic Demagnetization Refrigerator (CADR) design by building and testing a prototype. This new technology has the potential to greatly reduce the cost of ultra-low temperature research. Currently, if a researcher needs to keep an experiment below 0.1K for more than a few days, there is only one viable technology: Dilution Refrigerators. These refrigerators rely on the very rare isotope He-3 (largely sourced from Tritium decay within the nuclear stockpile) and are quite expensive ($350,000 or more). The technology to be developed in Phase I promises to reduce this cost significantly by avoiding the complexity, size, infrastructure requirements, and He-3 reliance of Dilution Refrigerators. The envisioned CADR has the potential to help enable cost-effective quantum computing, the wide deployment of hyper-sensitive detectors for tracking nuclear material, the creation of quantum-information sensors critical to certain cryptographic schemes, in addition to other outcomes heretofore unknown.The intellectual merit of this project is the creation of a revolutionary ultra-low temperature refrigerator. During this Phase I effort, a prototype refrigerator will be created which demonstrates the basic working principles of this new design. This prototype refrigerator will operate using a single stage of Gadolinium Gallium Garnet (GGG) as a refrigerant for continuously lifting heat from sub-Kelvin temperatures to a 3K pulse tube. This refrigerator will serve as a proof-of-concept for a two-stage refrigerator to be designed and tested in Phase II. The future two-stage refrigerator will use GGG to precool ferric ammonium alum (FAA) in order to reach 0.1 Kelvin and below. The research in this Phase I effort will feature an iterative process of subsystem characterization (heat switches, magnetic shielding, etc.), design, build and test. The Phase I effort is focused on answering the feasibility questions surrounding the engineering of this CADR while leaving 100 mK temperatures, multi-stage cooling, and deep analysis to Phase II. A successful proof of concept refrigerator to be demonstrated and characterized at the end of Phase I will move useful heat (goal of 0.5 milliwatts) from sub-Kelvin temperatures to a 3K pulse tube.