CROSSED LOOP, LOOP GAP RESONATOR FOR EPR OF BIOMOLECULES

电子顺磁共振(EPR)谱在核磁共振研究中的应用 生物分子的研究往往受到信号/噪声的限制。 现有的乐器。现代脉冲和多频电子顺磁共振 技术重要的是分离微波泵浦功率和观测 空间和/或时间中的自旋共振信号。这需要 含样品谐振器的精密微波匹配 微波源和探测器。所有这些都必须在 一种灵活适应样品类型和温度的方式 在研究生物系统时遇到的。 提出了一种创新的交叉环路来解决这些问题 环隙谐振器(CLLGR)，与低温制冷器紧密耦合 低噪声放大器。CLLGR将接受标准的4 mm外径石英样品 管子。机械调谐的组合，以确保 微波模式，以及改变耦合程度的电气调谐， 将产生一个非常方便(用户友好)的光谱仪系统。 最初的实施将在S频段(2-4 GHz)。这其中的每一个 特点：CLLGR，正交性的机械调谐类型， 紧耦合低噪声放大器，以及电子调谐 阻抗匹配，是对标准(和商业)EPR的背离 分光计设计。履约证明将通过以下申请获得 高自旋钴(II)取代金属蛋白的脉冲EPR

The application of electron paramagnetic resonance (EPR) spectroscopy to the study of biomolecules frequently is at the limit of the signal/noise of existing instruments. For modern pulsed and multifrequency EPR techniques it is important to separate microwave pump power and observed spin resonance signals in space and or in time. This requires sophisticated microwave matching of the sample-containing resonator to the microwave source and to the detector. All of this must be accomplished in a way that flexibly adapts to the types of samples and temperatures encountered in the study of biological systems. It is proposed to solve these problems with an innovative crossed-loop loop gap resonator (CLLGR), closely coupled with a cryogenically cool able low noise amplifier. The CLLGR will accept standard 4 mm OD quartz sample tubes. A combination of mechanical tuning to ensure orthogonality of the microwave modes, and electrical tuning to vary the degree of coupling, will result in a very convenient (user friendly) spectrometer system. Initial implementation will be at S-band (2-4 GHz). Each of these features: the CLLGR, the type of mechanical tuning of orthogonality, the closely-coupled low noise amplifier, and the electronic tuning of impedance match, is a departure from standard (and commercial) EPR spectrometer design. Proof of performance will be the application to pulsed EPR of high-spin cobalt(II)-substituted metalloproteins.