Exchange gas cryostat system for electrical characterization of materials at low temperatures

在过去的30年里，人们对新的超导材料家族的兴趣与日俱增，这些材料在低温(约零下200摄氏度)下无电阻导电。超导体现在正在走向成熟，很快就会出现在许多商业产品中。这些材料的性能和经济性很大程度上依赖于这些材料的电性能和机械性能，而这些性能又是温度和磁场的高度函数。因此，实现对超导体的有效技术利用的一个先决条件是获得对其物理性质的详细了解。蒙特利尔理工学院超导与磁性实验室(LSM)促进了超导科学技术的发展，特别是在能源、交通和生物医学等各个领域的应用。它的研究项目在加拿大是独一无二的，因为它专注于商业超导材料(大型样品)的表征，这些材料被用于广泛的新兴应用，例如无损电力传输电缆。该提案中要求的设备是一个变温低温恒温器系统，能够在4.2K(-269摄氏度)和室温之间冷却超导样品，以支持与当地和国际合作伙伴开展的应用超导研究。更具体地说，新设备将允许执行两种主要类型的实验：1)传输电流测量，2)磁化测量。第一类实验对冷却功率要求很高。这导致我们选择了交换气体低温恒温器技术。请注意，新设备将取代已到使用寿命尽头的旧设备。新的低温恒温器还将与现有的实验室仪器和电磁铁兼容，它将大大改善目前研究计划中可以进行超导体表征的温度范围。它还将支持新兴课题的研究，如1)基于高温超导导线的高场磁体，以及2)液氢和超导设备的协同作用，以实现更环保的航空。这将使蒙特利尔理工学院和LSM在超导体的表征方面处于全球独一无二的地位，并应能满足未来10至15年的所有研究和培训需求。在将使用所需设备执行的项目的实际影响中，人们可以列举：1)利用血管中药物的磁控来治疗新型癌症，2)为更绿色的飞机开发电力推进系统，3)产生用于医学成像、粒子加速器(用于高能物理研究)、核聚变等的超高磁场。

In the last 30 years, there has been a rising interest for new families of superconducting materials, these materials that conduct electricity without resistance at low temperatures (around -200 degrees Celsius). Superconductors are now getting mature and will soon be present in numerous commercial products. The performance and the economics of the applications strongly depends on the electrical and mechanical properties of these materials, which are highly function of temperature and magnetic field. Thus, a prerequisite to achieve an efficient technological use of superconductors is to acquire a detailed knowledge of their physical properties. The Laboratory of Superconductivity and Magnetism (LSM) of Polytechnique Montreal advances the science and technology of superconductivity and particularly its applications in various fields, namely energy, transportation and biomedical. Its research program is unique in Canada owing to its focus on the characterization of commercial superconducting materials (large-scale samples) that are used in a wide range of emerging applications, for instance loss-free power transmission cables. The equipment asked for in this proposal is a variable temperature cryostat system capable of cooling superconducting samples at temperatures between 4.2 K (-269 Celcius) and room temperature, in order to support research in applied superconductivity, carried out with local and international partners. More specifically, the new equipment will allow performing two main types of experiments: 1) transport current measurements, and 2) magnetization measurements. The first type of experiment is very demanding in terms of cooling power. This led us to choose an exchange gas cryostat technology. Note that the new equipment will replace a former one that has reached its end of life. The new cryostat will also be compatible with the existing laboratory instrumentation and electromagnets, and it will improve substantially the range of temperature at which the characterization of superconductors can be performed in the current research program. It will also support research in emerging topics like 1) high-field magnets based on high temperature superconducting wires, and 2) synergetic action of liquid hydrogen and superconducting devices for greener aviation. That will put Polytechnique Montreal and the LSM in a unique position worldwide regarding the characterization of superconductors and should fulfill all research and training needs for the next 10 to 15 years. Among the practical impacts of the projects that will be carried out with the equipment requested, one can cite: 1) new types of cancer treatments using magnetic steering of drugs in blood arteries, 2) the development of electric propulsions systems for greener aircrafts, 3) the generation of very high magnetic fields to use in medical imaging, particle accelerators (for research in high-energy physics), nuclear fusion, etc.