A Compact, 395 GHz Traveling Wave Tube (TWT) Amplifier for DNP-NMR and EPR Spectroscopy

项目总结/摘要 我们提出了一种紧凑的，具有成本效益的行波管（TWT）放大器在395 GHz的1.5 W 用于动态核极化的连续波功率和20 GHz瞬时带宽 (DNP)增强固体和溶液NMR和电子顺磁共振（EPR） 谱使用DNP，NMR实验中固有的小信号强度可以增强高达 两个数量级这种显著增加的总体灵敏度将非常有益于分析。 核磁共振波谱学的应用以及利用核磁共振测定生物大分子的结构 方法. 目前，DNP用低功率固态源（其输出功率限于几个 mW，频率> 300 GHz）和20-30 K范围内的低温（以补偿低 微波功率）或使用可产生50 W功率的大型回旋管系统。回旋管是 昂贵，并且不具有足够的调谐带宽（<0.1%），这是研究广泛的 DNP实验，因此需要昂贵的扫描线圈的NMR磁体。拟建的TWT将 解决上述所有问题。行波管的成本预计不到回旋管成本的四分之一 系统，提供20 GHz瞬时带宽，将是一个紧凑的桌面系统。这些 这些优势将使更多的研究人员能够利用DNP提供的灵敏度提升 在核磁共振实验中。 在第一阶段，我们将设计、建造和测试一个原型系统。这种系统的成功演示 将使我们能够在第二阶段开发出性能上级的商业产品。的 技术是可扩展的，并且可以在高达527 GHz（800 MHz NMR）的频率下使用。更高的峰值 功率版本的设备将推进国家的最先进的高场EPR光谱。作为至强 根据该项目的结果，我们预计Bridge 12将为DNP提供395 GHz（600 MHz NMR）的商用行波管， NMR和EPR光谱。这将大大加快生物大分子的结构测定， 与美国国立卫生研究院资助的人类疾病研究相关。

Project Summary / Abstract We propose to develop a compact, cost-effective Traveling Wave Tube (TWT) amplifier at 395 GHz with 1.5 W continuous wave power and 20 GHz instantaneous bandwidth for application in Dynamic Nuclear Polarization (DNP) enhanced solid-state and solution-state NMR and Electron Paramagnetic Resonance (EPR) spectroscopy. With DNP, the inherently small signal intensities in a NMR experiment can be enhanced by up to two orders of magnitude. This significantly increased overall sensitivity will be highly beneficial for analytical applications of NMR spectroscopy as well as in the structure determination of bio-macromolecules using NMR methods. Currently, DNP is performed with either low power solid-state sources (whose output power is limited to a few mW at frequencies > 300 GHz) and at low temperatures in the range of 20-30 K (to compensate for low microwave power) or with large, gyrotron systems which can generate 50 W of power. Gyrotrons are expensive and do not possess sufficient tuning bandwidth (<0.1%) necessary for investigating a wide range of DNP experiments and thus require expensive sweep coils in the NMR magnets. The proposed TWT will address all the above concerns. The TWT is expected to cost less than one-fourth of the cost of a gyrotron system, provide 20 GHz of instantaneous bandwidth and will be a compact table-top system. These advantages will allow a larger number of researchers to take advantage of the sensitivity boost offered by DNP in NMR experiments. In Phase I, we will design, build and test a prototype system. The successful demonstration of such a system in Phase I will enable us to develop a commercial product in Phase II with superior performance. The technology is scalable and can be used at frequencies as high as 527 GHz (800 MHz NMR). A higher peak power version of the device will advance the state-of-the-art in high field EPR spectroscopy. As an ultimate result of this project, we expect Bridge12 to offer a commercial TWT at 395 GHz (600 MHz NMR) for DNP- NMR and EPR spectroscopy. This will greatly accelerate structure determination of bio-macromolecules of relevance to human disease research funded by NIH.