Miniature milli-kelvin cryo-cooler

我们建议开发和建造世界上第一台毫开尔文制冷机，以改变毫开尔文温度域的使用方式，就像4k制冷机用于液氦区域一样。它将使那些没有低温经验的人能够很容易地在台式系统中获得极低的温度。我们建议构建一个小型冷却器模块，一个连续绝热退磁制冷（cADR），它将任何4 K的冷冷却器扩展到毫开尔文（<100 mK）的冷冷却器。目前的4 K脉冲管冷却器可以在2小时内从室温达到4 K，我们预计cADR还需要2小时才能达到<100 mK，从而在4小时内从室温完全冷却到<100 mK。通过控制ADR的各种磁场，所提出的冷冻冷却器模块可以在从附加的4 K冷冻冷却器的基本温度到<100 mK的任何地方提供高度稳定的温度。因此，这代表了一个完整的冷冻冷却器解决方案，因此对于仍然庞大而笨重的技术来说非常易于使用。Mullard空间科学实验室（MSSL）对未来太空任务的ADR技术进行了大量投资，从而实现了地面系统的这一提议。

We propose the development and construction of the world's first milli-Kelvin cryo-cooler, transforming the use of the milli-Kelvin temperature domain in the same way 4 K cryo-coolers have for the liquid helium region. It will enable those inexperienced with such low temperatures to easily access very low temperatures in a bench top system. We propose to construct a small cooler module, a continuous adiabatic demagnetisation refrigeration (cADR) which will extend any 4 K cryo cooler to a milli-Kelvin (<100 mK) cryo cooler. Current 4 K pulse tube coolers can reach 4 K from room temperature within 2 hours, we anticipate a further 2 hours for the cADR to achieved <100 mK, giving a complete cool down from room temperature to <100 mK in 4 hours. By controlling the ADR's various magnetic fields, the proposed cryo-cooler module can provide a highly stable temperature anywhere from the base temperature of the attached 4 K cryo-cooler to <100 mK. This therefore represents a complete cryo-cooler solution and thus extreme ease of use for a technology which is still large and cumbersome. The technology to enable this proposal for a ground based system has come about by the large investment in developing ADR technology for future space missions at the Mullard Space Science Laboratory (MSSL).