EDEN - A Prototype 10mK Dry Dilution Refrigerator

点击翻译按钮获取中文摘要

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.