Supplement to NATIONAL CENTER FOR ADVANCED ESR TECHNOLOGY

描述（由申请人提供）：本提案是根据NCRR资助公告：PAR-12-046，对母基金R41RR016292资助进行竞争性修订，P41中心：国家生物医学中心先进ESR技术。本提案是一个新技术项目，不包括在母体资助中，但极大地有利于母体资助的目标，特别是技术研究与开发（TR&D）项目：脉冲偶极ESR蛋白质和蛋白质复合物的结构（PDS-ESR），该项目涉及改进现有的和开发新的距离测量技术，用于生物分子的结构研究。新的项目是开发复合脉冲的方法，在核磁共振中很常见，应用于ESR，这需要更短的脉冲宽度和更快的自旋弛豫。现在使用新的泰克任意波形发生器（AWG）可以实现以低于ns的分辨率调制微波脉冲。它将使距离测量的双量子相干(DQC)-ESR方法中的脉冲具有更好的光谱覆盖范围，这需要非选择性脉冲。它将使双电子-电子共振（DEER）方法所需的精心设计的选择性脉冲成为可能。

DESCRIPTION (provided by applicant): This proposal is for a competitive revision, under NCRR funding announcement: PAR-12-046, of the parent grant R41RR016292 funding, P41 Center: National Biomedical Center for Advanced ESR Technology. This proposal is for a new technology project, not included on the parent grant, but which greatly benefits the aims of the parent grant, in particular Technology Research and Development (TR&D) Project: Structure of Proteins and Protein Complexes by Pulse Dipolar ESR (PDS-ESR), which is concerned with improving existing and developing new distance measurement techniques for structural studies on biomolecules. The new project is to develop methods of composite pulses, common in NMR, to be applied to ESR, which requires much shorter pulse widths and is subject to much faster spin-relaxation. This is now possible using a new Tektronix Arbitrary Waveform Generator (AWG) that will enable the modulation of the microwave pulses with sub-ns resolution. It will enable better spectral coverage by the pulses in the double-quantum coherence (DQC)-ESR method for distance measurements, which requires non-selective pulses. It will enable well-designed selective pulses required for the double electron-electron resonance (DEER) method. This will enhance signal-to-noise and suppression of unwanted signals and artifacts, thereby improving these methodologies. The AWG will be integrated into the pulse ESR spectrometer with due consideration of the letter's detailed performance. Monitoring of the composite pulsing at key positions in the microwave bridge, with the help of a sufficiently wide-bandwidth digital sampling oscilloscope (DSO), will permit automatic retuning of the AWG to modify as needed the composite pulses to guarantee the quality of the pulses that actually reach the sample. This project will involve a synergistic interaction, driven by the needs of the Driving Biomedical Projects (DBP's) as in the Parent Grant. Careful tests will be made of this new composite-pulse technology to demonstrate how it significantly improves the distance measurements and allows new and more challenging studies included in the DBP's to be carried out.