An Integrated THz System for DNP-enhanced NMR Spectroscopy

描述（由申请人提供）：拟议的研究重点是开发一种DNP-NMR系统，用于400 MHz的动态核极化（DNP）增强固态核磁共振光谱。高分辨率结构对于理解生物大分子的复杂功能至关重要，核磁共振波谱是此类信息的主要来源。然而，该方法固有的灵敏度低，需要较长的采集时间才能获得足够的数据质量。DNP是一种通过太赫兹辐射将高热电子极化转移到周围原子核的方法，可以将核磁共振灵敏度提高两到三个数量级。使用DNP，通常需要数天或数周的信号平均实验可以在几分钟或几小时内完成。它使研究人员能够在短短几小时内完成原本不可能完成的实验，例如高精度距离测量或记录未标记分子的2D 13C-13C相关光谱。在这个方案中，我们提出了一个基于263 GHz回旋管源的400 MHz DNP系统，该系统集成在核磁共振磁体中。我们的产品不需要额外的，昂贵的超导磁体。这是可能的，因为电流（宽口径）核磁共振磁体在探头上方提供了足够的空间来集成和操作回旋管源。这种创新的回旋管专为DNP应用而设计，提供足够的功率和足够的频率调谐带宽，以消除其他DNP系统所需的超导扫描线圈。所提出的创新技术为每台设备节省了80万美元的成本，并将使DNP成为一种更经济实惠的方法。在第一阶段，我们将进行263 GHz集成太赫兹源的机械和电气设计，并根据其核磁共振性能选择腔内微调线圈磁铁组件。在第二阶段，将制造回旋管源，包括低温核磁共振探头在内的完整DNP系统将集成在400 MHz核磁共振磁体中。作为这个项目的结果，我们期望一个完整的基于Bridge12的集成回旋管源的400 MHz DNP系统，我们期望在常规测量中信号增强bb100。虽然该产品最初是针对学术市场，但我们预计它将为学术界和工业界更广泛地接受该技术奠定基础，并将DNP的好处带给更广泛的科学受众。

DESCRIPTION (provided by applicant): The proposed research focuses on the development of a DNP-NMR system for Dynamic Nuclear Polarization (DNP) enhanced solid-state NMR spectroscopy at 400 MHz. High-resolution structures are essential to the understanding of the complex functions of bio-macromolecules and NMR spectroscopy is a major source for such information. However, the method suffers from an inherently low sensitivity and long acquisition times are required to achieve sufficient data quality. DNP, a method in which the high, thermal electron polarization is transferred to surrounding nuclei by THz irradiation of the sample, can boost the NMR sensitivity by two or three orders of magnitude. With DNP, experiments that typically require days or weeks of signal averaging can be performed in minutes or hours. It enables researchers to do experiments that are otherwise impossible to perform, such as high-precision distance measurements or recording 2D 13C-13C correlation spectra of unlabeled molecules in just hours. In this proposal we present a novel 400 MHz DNP system based on a 263 GHz gyrotron source that is integrated into the NMR magnet. Our product does not require an additional, expensive superconducting magnet. This is possible, because current (wide-bore) NMR magnets provide sufficient space right above the probe to integrate and operate the gyrotron source. This innovative gyrotron tube is specifically designed for DNP applications, provides sufficient power and has adequate frequency tuning bandwidth to eliminate the superconducting sweep coil that is necessary in other DNP systems. The presented innovations result in cost savings of >$ 0.8 million per unit and will make DNP a much more affordable method. During Phase I we will perform the mechanical and electrical design of the 263 GHz integrated THz source and select a cavity trim coil magnet assembly based on its NMR performance. During Phase II the gyrotron source will be fabricated and the complete DNP system including the low-temperature NMR probe will be integrated in the 400 MHz NMR magnet. As a result of this project, we expect a complete 400 MHz DNP system based on Bridge12's integrated gyrotron source and we expect signal enhancements of >100 in routine measurements. Although the product is initially targeted towards an academic market we expect that it will lay the foundation for a much broader acceptance of the technology in academia and industry and will bring the benefits of DNP to a much broader scientific audience.