MRI: Development of an Innovative EPR Spectrometer

凭借该奖项，丹佛大学的Sandra Eaton教授和同事Gareth Eaton将开发一种创新的数字电子顺磁共振（EPR）光谱仪，该光谱仪可以使用AWG（任意波形发生器）源和数字检测在9至10 GHz的任何频率下工作。一台数字光谱仪将能够在可变频率下进行大范围的脉冲、快速扫描和连续激发EPR实验，而不是像目前那样需要多台仪器来处理不同频率。用户将能够在用户友好的软件中实现新的实验，而不需要昂贵的新硬件。数字检测提高了信噪比，减少了数据采集时间。单个谐振器（探头）将是窄带的，以最大限度地提高灵敏度。光谱仪将有一系列易于互换的谐振器模块，用于目前广泛使用的频率（如9.5 GHz）和目前没有光谱仪的频率（如4 GHz）的实验，但理论预测这将是非常有价值的。这项建议的目的是加强各级的研究、培训和教育。项目包括硝基电子自旋弛豫的频率依赖，活性氧超氧化物的自旋俘获，以及在量子计算中潜在应用的钻石缺陷中心的表征。EPR是研究未配对电子分子的首选方法。应用范围从有机自由基和过渡金属配合物，到纳米技术和太阳能转换材料，蛋白质中金属位点的表征，以及聚合物、蛋白质和核酸中的长距离测量。数字化EPR光谱仪更大的灵活性将使其在更广泛的应用中更有用。新的数字EPR光谱仪的详细设计将公布，使其可供其他研究实验室和商业供应商使用，这将为EPR光谱学开辟新的前景。此外，该项目将通过提供前沿的跨学科学习环境，为劳动力发展做出贡献。学生将有机会与工程师、物理学家和化学家互动。此外，来自附近的里吉斯大学（Regis University）的学生（第一代大学生占很大比例）将定期使用EPR实验室。

With this award from the Major Research Instrumentation Program, Professor Sandra Eaton from University of Denver and colleague Gareth Eaton will develop an innovative digital electron paramagnetic resonance (EPR) spectrometer that can operate at any frequency up to 9 to 10 GHz using an AWG (arbitrary waveform generator) source and digital detection. A single digital spectrometer will be capable of performing a wide range of pulse, rapid-scan, and continuous-excitation EPR experiments at variable frequencies, instead of requiring multiple instruments for different frequencies as is currently the case. Users will be able to implement new experiments in user-friendly software without requiring costly new hardware. Digital detection improves signal-to-noise and decreases data acquisition time. Individual resonators (probeheads) will be narrow-banded to maximize sensitivity. The spectrometer will have a series of readily interchangeable resonator modules for experiments at frequencies that are currently widely used (such as 9.5 GHz) and ones (such as 4 GHz) where spectrometers are not currently available, but which theory predicts will be very valuable. The proposal is aimed at enhancing research training and education at all levels. Projects include the frequency dependence of nitroxyl electron spin relaxation, spin trapping of the reactive oxygen species superoxide, and characterization of defect centers in diamonds with potential applications in quantum computing. EPR is the method of choice for studying molecules with unpaired electrons. Applications range from organic radicals and transition metal complexes, to materials for nanotechnology and solar energy conversion, characterization of metal sites in proteins, and measurement of long distances in polymers, proteins, and nucleic acids. The much greater flexibility of a digital EPR spectrometer will make it more useful in a wider range of applications. The detailed design of the new digital EPR spectrometer will be published to make it available to other research laboratories and to commercial vendors, which will open up new vistas for EPR spectroscopy. In addition, the project will contribute to workforce development by providing a cutting-edge interdisciplinary learning environment. Students will have the opportunity to interact with engineers, physicists, and chemists. Furthermore, students from nearby Regis University, with a high proportion of first-generation college students, will use the EPR laboratory on a regular basis.