Compact, deadtime-free, stray-field NMR sensor

杂散场核磁共振是一种在实验室对材料进行无损检测的技术。它在科学界和工业界都有很好的地位。主要应用于聚合物和相关材料的质量控制和老化，包括PE管、PVC地板、汽车轮胎、沥青路面、人体皮肤和食品。在许多情况下，这些材料可以使用Magritek和Bruker等供应商基于商业实验室的技术进行维护。然而，当前传感器的死区时间太长，无法用于建筑材料中的结合水，如水泥、风车机翼上的玻璃和碳纤维增强聚合物复合材料，以及绘画和乐器上的清漆。此外，物质文化遗产分析和户外测量等新兴应用将极大地受益于改进设备，使其能够在偏远地区和恶劣环境条件下运行，并确定核磁共振松弛/扩散与应用参数之间的相关关系。该项目的主要科学目标是实现将紧凑型杂散场核磁共振传感器的死区时间从目前的70微米S大幅减少到10毫米访问深度下的20微米S以下。此外，我们将研究通过缩小每个元件并将其集成到单个设备中来实现光谱仪、传感器和用于深度剖析的机械平移工作台小型化的策略。除了降低功率消耗以允许汽车电池运行的额外研究外，还将包括用于使核磁共振设备与对象精确平行对准的传感器，以及显著改善装置的坚固性，例如通过增加其对电磁干扰的容忍度，研究仪器将被研究并制作原型，从而实现杂散场核磁共振的全新现场应用。这包括在线生产线上的无损材料测试，以及在博物馆、遗产和户外挖掘现场的应用。一个由三名绩效指标组成的跨学科小组将确保设想的原型与现场和实地要求相一致，并在实验室测试和试点研究中加以验证。

Stray-field NMR is a technique for nondestructive materials testing in the laboratory. It is well established in the scientific community and industry. Primary applications are found in quality control and aging of polymers and related materials, including PE pipes, PVC flooring, car tires, asphalt pavements, human skin, and food products. These materials can, in many cases, be serviced with commercial laboratory-based technology from vendors such as Magritek and Bruker. However, the dead time of the current sensors is too long for useful materials analysis applied to e. g. bound water in building materials such as cement, glass- and carbon-fiber-reinforced polymer composites in windmill wings, and varnish on paintings and musical instruments. Moreover, emerging applications such as the analysis of tangible cultural heritage and outdoor measurements would greatly benefit from improvements concerning the equipment to function in remote locations and under adverse environmental conditions and the identification of relevant correlations between NMR relaxation/diffusion and application parameters. The main scientific goal of this project is to achieve a significant reduction of the dead time of compact stray-field NMR sensors from currently 70 µs to less than 20 µs at 10 mm depth of access. Moreover, we will investigate strategies for miniaturizing the spectrometer, sensor, and mechanical translation stage for depth profiling by shrinking each element and integrating them into a single device. Together with additional research on reducing the power consumption to allow for operation from a car battery, on including a sensor for the precise parallel alignment of the NMR device with the object, and significantly improving the ruggedness of the setup, e. g. by increasing its tolerance to electromagnetic interference, a research instrument will be investigated and prototyped that enables entirely new in-field applications of stray-field NMR. This includes nondestructive materials testing at production lines online, as well as applications in museums, heritage, and excavation sites outdoors. An interdisciplinary team of three PIs will ensure compatibility of the envisioned prototype with in situ and in-field requirements and validate it in laboratory tests and pilot studies.