EDEN - A Prototype 10mK Dry Dilution Refrigerator

许多先进的科学仪器需要冷却到接近绝对零度（0 K）的温度。这种设备用于先进的磁共振成像，扫描probemicroscopy和量子计算的超导性的产生。实现这种低温的设备-稀释制冷机-通过在封闭系统中以逐渐降低的温度蒸发液氦（He）来工作，并通过热交换器连接。在传统的“湿”系统中，初始冷却是通过简单地浸入液态氦中来实现的。然而，氦是一种有限的资源。目前世界消耗量的约三分之一由美国的He储备提供，该储备建立于1925年，将在2020年至2030年之间耗尽。这种情况意味着许多低温设备的新用户无法在超低温下工作，被迫选择“干式”稀释制冷机。这些系统不包含任何“开放式”He。最初的冷却是提供封闭的系统，仍然包含氦，但需要在6个月左右的时间间隔少量补充，而不是每周的主要补充“湿”系统。ICE牛津需要资金来开发一个原型干稀释制冷机工作在<10 mK。他们已经成功地交付干稀释系统冷却到10，4K和1.5K。阿萨是一家新近进入市场的公司，他们在根据用户需求定制产品方面取得了成功。他们的原型将包括一个中间冷却级，这是越来越多地需要更高的功率冷却应用，如量子计算。它还将展示一个集成的高场，高均匀性，低衰减磁体用于MRI应用。它还将提供一个试验台，以演示目前正在其他地方开发的低温振动测量设备。一个成功的原型的影响将允许尖端的研究人员提供社会和经济效益使用低温设备不可持续的He消费。

Many advanced scientific apparatus needs cooling to temperatures approaching absolute zero(0K). Such apparatus is used in advanced magnetic resonance imaging, scanning probemicroscopy and generation of superconductivity for quantum computing. Equipment toachieve such low temperatures- dilution refrigerators- work by evaporating liquid helium (He)in closed systems at progressively lower temperatures, linked by heat exchangers. Intraditional “wet” systems, initial cooling is achieved simply by immersion in liquid He.However, He is a finite resource. Around 1/3 of current world consumption is supplied by theUS He reserve, which was set up in 1925 and will be exhausted between 2020 and 2030. Thissituation means that many new users of cryogenic equipment are prevented from performingwork at ultra-low temperatures, and are forced to opt for “dry” dilution refrigerators.These systems do not contain any “open” He. Initial cooling is provided closed systems,which still contain helium but require minor replenishment at ~6 month intervals, rather thanweekly major replenishment of “wet” systems.ICE Oxford need funding to develop a prototype dry dilution refrigerator working at <10mK.They have already successfully delivered dry dilution systems cooling to 10, 4K and 1.5K. Asa recent market entrant they have built success on customising to user requirements. Theirprototype will incorporate an intermediate cooling stage, which is increasingly required forhigher power cooling applications, such as quantum computing. It will also demonstrate anintegrated high field, high homogeneity, low decay magnet for use in MRI applications. It willalso provide a test bed to demonstrate low temperature vibration measurement equipment,currently under development elsewhere. The impact of a successful prototype will be to allow cutting-edge researchers to deliver societal and economic benefits using cryogenic equipmentwithout unsustainable He consumption.