A THz Resonator for Solid-State DNP-NMR Spectroscopy

描述（由申请人提供）：拟议的研究重点是开发用于动态核极化（DNP）增强固态NMR光谱（ssNMR）的太赫兹（THz）谐振器。使用DNP，NMR实验中固有的小信号强度可以增强几个数量级。这种显著增加的整体灵敏度对于ssNMR光谱学的许多应用以及生物大分子的结构表征将具有很大的价值。在过去的十年中，DNP已被证明是一种强大的方法，可以在世界各地的固态NMR（SSNMR）实验室中增加高场信号强度。然而，目前样品直接被THz辐射照射，这是一个非常低效的过程，需要高功率THz源来有效地驱动THz辐射。 DNP过程。常见的假设是，基模谐振器的横向尺寸（对于198 GHz，半径约为0.75 mm，对应于300 MHz 1H）太小而不能容纳通常用于ssNMR光谱学的样品尺寸，例如魔角旋转（MAS）转子。在第一阶段SBIR提案中提出的创新想法集中在开发一种新型谐振结构，该结构将增加THz感应B1 e场强并最小化所需的THz功率，同时不干扰NMR探针的RF结构，从而保持探针的线形完整性。这对于高场DNP光谱学（> 600 MHz，1H）特别重要，其中减少所需太赫兹功率的量将允许使用紧凑且具有成本效益（~ 40，000 - 50，000美元）的固态源，而不是大型且昂贵的（~ 1美元）回旋管系统。此外，拟议的研究可能最终导致未来脉冲DNP实验所需的THz谐振器。这种探针的成功开发将使DNP增强的ssNMR光谱学在结构生物学，药物研究和分析化学中迅速扩散，这些都是美国国立卫生研究院资助的许多项目的兴趣。

DESCRIPTION (provided by applicant): The proposed research focuses on the development of a terahertz (THz) resonator for Dynamic Nuclear Polarization (DNP) enhanced solid-state NMR spectroscopy (ssNMR). With DNP, the inherently small signal intensities in an NMR experiment can be enhanced by several orders of magnitude. This significantly increased overall sensitivity will be of great value for many applications of ssNMR spectroscopy as well as the structural characterization of bio-macromolecules. In the last decade, DNP has proven to be a robust method to increase high-field, in solid-state NMR (SSNMR) signal intensities laboratories around the world. However, currently the sample is directly illuminated by the THz radiation, a very inefficient process that requires high-power THz sources to efficiently drive the DNP process. The common assumption is, that the transverse size of a fundamental mode resonator (radius ~0.75 mm for 198 GHz, corresponding to 300 MHz 1H) is too small to accommodate sample sizes that are typically used in ssNMR spectroscopy such as Magic Angle Spinning (MAS) rotors. The innovative idea proposed in this Phase I SBIR proposal focuses on the development of a novel, resonance structure which will increase the THz induced B1e field strength and minimize the amount of required THz power while not interfering with the RF structure of the NMR probe and thus maintaining lineshape integrity of the probe. This is of specific importance for high-field DNP spectroscopy (> 600 MHz, 1H) where reducing the amount of necessary terahertz power will allow the use of compact and cost-effective (~$40,000 - 50,000) solid state sources instead of large and expensive (~1$M) gyrotron systems. In addition the proposed research could eventually lead to THz resonators that are required for future pulsed DNP experiments. The successful development of this probe will enable the rapid proliferation of DNP-enhanced ssNMR spectroscopy for structural biology, pharmaceutical research and analytical chemistry, which are of interest in many projects funded by the U.S. National Institutes of Health.