140 GHz Gyroamplifier for Time Domain DNP and EPR

描述（由申请人提供）：我们建议设计和建造一个100 W，140 GHz的回旋管放大器，并将其应用于时域DNP/NMR和EPR实验。在过去的十年中，利用90-300 GHz范围内的高频微波的时域磁共振技术的全部功能已经大大扩展。具体而言，时域EPR和DNP/NMR实验已经成为阐明生物系统的结构，功能和动态特性的重要技术。然而，目前这些技术在高频下的充分实施受到微波功率缺乏的限制。该提案要求提供资金，以开发一种工作在140 GHz、带宽为1 GHz、饱和增益为35 dB的高功率回旋管放大器。回旋管放大器是特别有吸引力的，因为它能够扩展到更高的频率。低功率（30-60 mW）相位开关和脉冲形成网络（具有四相和<1 ns开关能力）将用作陀螺放大器的输入（驱动器）。这种陀螺放大器将使最近开发的电子-核交叉极化（CP）实验的全面实施和最近开发的低频（9-18 GHz）脉冲EPR技术的扩展到高频，用于测量自旋标记生物系统中的远程（15- 80埃）电子-电子偶极耦合。总而言之，本研究的具体目标可以分为三个部分： (1)100 W高频（140 GHz）回旋管放大器的研制。 (2)用BDPA/PS和三苯甲基/水甘油样品进行电子-核CP实验。 (3)使用双自由基自旋标记肽在140 GHz下进行多量子和SIFTER脉冲EPR实验。

DESCRIPTION (provided by applicant): We propose to design and build a 100 W, 140 GHz gyrotron amplifier and to apply it in time domain DNP/NMR and EPR experiments. During the last decade the repertoire of time domain magnetic resonance techniques that utilize high frequency microwaves in the 90-300 GHz regime has expanded considerably. Specifically, time domain EPR and DNP/NMR experiments have emerged as important techniques for elucidating the structure, function, and dynamic properties of biological systems. However, at present the full implementation of these techniques at high frequency is limited by the lack of microwave power. This proposal requests funding to develop a high power gyrotron amplifier operating at 140 GHz with a 1 GHz bandwidth and 35 dB of saturated gain. A gyrotron amplifier is particularly attractive because it is capable of extension to higher frequency. A low power (30-60 mW) phase switching and pulse forming network (with four phase and <1 ns switching capability) will be used as the input (driver) for the gyro-amplifier. This gyro-amplifier will enable the full implementation of a recently developed electron-nuclear crosspolarization (CP) experiment and the extension to high frequency of recently developed low frequency (9-18 GHz) pulsed EPR techniques for measuring long range (15-80Angstroms) electron-electron dipolar couplings in spin labeled biological systems. To summarize, the specific aims of the research can be divided into three parts: (1) Development of a 100 W, high frequency (140 GHz) gyrotron amplifier. (2) Implementation of electron-nuclear CP experiments with BDPA/PS and trityl/water glycerol samples. (3) Implementation of multiple quantum and SIFTER pulsed EPR experiments at 140 GHz using biradical spin labeled peptides.