Tunable 330 GHz Gyrotron for DNP/NMR

用于 DNP/NMR 的可调谐 330 GHz 回旋管

• 批准号: 7534949
• 负责人: RICHARD J TEMKIN
• 金额: $ 33.36万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-07 至 2010-08-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7534949
• 关键词: Complex; Coupling; Detection; Development; Electronics; Freezing; Frequencies; Hand; Laboratories; Magnetism; Mechanics; Methods; Noise; Nuclear; Principal Investigator; Research; Sampling; Science; Signal Transduction; Solutions; Source; System; Techniques; Temperature; Vacuum; Variant; base; cold temperature; cost; design; instrumentation; magnetic field; melting; microwave electromagnetic radiation; nitroxyl; novel; programs; research study; solid state; solid state nuclear magnetic resonance; voltage

We propose a program of research to design, build and operate a tunable 330 GHz gyrotron oscillator for CW DNP/NMR research. There are a number of 500/89 magnets in solid-state NMR laboratories around the world and these could be used with a 330 GHz microwave source to perform DNP/NMR. However, all of the known DNP mechanisms require that the magnetic field be adjusted to the peak of the enhancement curve to optimize the signal to noise ratio (S/N) of the experiment. This necessitates either that the magnetic field be swept with a sweep coil on the magnet, or that the microwave frequency be adjusted. In NMR systems using magnets with sweep coils, DNP/NMR research can be conducted with fixed frequency gyrotrons. However, the vast majority of NMR magnets in existence do not have sweep coils and it is impractical to retrofit these systems. Therefore, a tunable gyrotron oscillator appears to be the approach of choice for laboratories with this type of magnet. We propose to design and fabricate a 330 GHz gyrotron that can be tuned over a range of ¿0.75 GHz which will permit coverage, for example, of the TEMPO EPR spectrum where the peaks in the enhancement curve will be separated by about 710 MHz. The tunable gyrotron oscillator will utilize a novel magnetic field tuning approach based on the excitation of high order axial modes of the resonator. Frequency tuning of ¿0.9 GHz has been recently demonstrated on a 250 GHz gyrotron oscillator here at MIT. The yrotron design will, in principle, be scalable to higher frequencies for application to 600 to 900 MHz where wide-bore magnets are currently available.

我们提出了一个研究计划，设计，建造和操作一个可调谐的330 GHz回旋振荡器的连续波 DNP/NMR研究。有一些500/89磁铁在固态核磁共振实验室周围， 这些可以与330 GHz微波源一起使用以执行DNP/NMR。然而，所有 已知的DNP机制需要将磁场调节到增强曲线的峰值 优化实验的信噪比。这就需要磁场 用磁体上的扫描线圈扫描，或者调整微波频率。在NMR系统中， 由于使用带有扫描线圈的磁体，DNP/NMR研究可以用固定频率的回旋管进行。然而，在这方面， 现有的绝大多数NMR磁体不具有扫描线圈 系统.因此，可调谐回旋振荡器似乎是实验室的选择方法， 这种磁铁。我们建议设计和制造一个330 GHz的回旋管，可以在一个范围内调谐， <$0.75 GHz，这将允许覆盖，例如，克里思EPR频谱，其中， 增强曲线将相隔约710 MHz。可调谐回旋振荡器将利用一种新颖的 基于谐振器高阶轴向模式激励的磁场调谐方法。频率 最近在麻省理工学院的250 GHz回旋振荡器上演示了<$0.9 GHz的调谐。的 原则上，回旋管设计将可扩展到更高的频率，以应用于600至900 MHz，其中 目前可获得宽孔磁体。