High Power 200 GHz Pulsed/Continuous Wave (CW) Microwave Source for Dynamic Nuclear Polarization (DNP) Spectroscopy

用于动态核极化 (DNP) 光谱分析的高功率 200 GHz 脉冲/连续波 (CW) 微波源

• 批准号: EP/K011944/1
• 负责人: Mark Newton
• 金额: $ 6.38万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FK011944%2F1
• 关键词: Power; 200; GHz; Pulsed; Continuous

Our vision is to create a spectrometer for Nuclear Magnetic Resonance (NMR) that can detect signals that are hundreds of times weaker than can be achieved with even the very best conventional spectrometers. NMR methods are firmly established as a primary analytical tool in chemistry, are increasingly influential for characterisation in materials science and have revolutionised medical imaging. Despite the great success of NMR there remains a huge demand to push the boundaries by increasing the sensitivity and speed of the technique. This will enable NMR to be used in the study of a broad range of problems, including catalysis, batteries and fuel cells where today its impact is limited through lack of sensitivity. Furthermore, it is widely appreciated that structural information is key for understanding biological processes (e.g. protein folding, signal transduction etc.) and many problems will only be soluble if the sensitivity of NMR is dramatically increased. Dynamic Nuclear Polarisation (DNP) offers the exciting possibility to greatly increase the sensitivity of NMR by exploiting the inherently much larger polarisation of electron spins as compared to nuclear spins (e.g. ~ 2500 times for 13C). The DNP infrastructure at Warwick was funded by a £3.74M Basic Technology project (EP/D045967/1). All components of the DNP systems developed functioned at or above their design targets, except for the gyrotron microwave source which did not meet the necessary power/stability requirements for routine operation/exploitation. Nevertheless, large enhancements (60x) were achieved. The proposed new "turn-key" microwave source will provide significantly enhanced performance, is much more stable, agile, versatile and has significantly lower running costs than the gyrotron microwave source used to date. It will enable the continued rapid development and exploitation the DNP capabilities at Warwick. Development work will be done in collaboration with researchers at the Universities of Nottingham, St Andrews and Southampton while the enhanced DNP capabilities will be exploited by the wider vibrant UK MR community who will have access to a tool which enables research on systems previously out of reach. The research impact will be significant since the sensitivity enhancements in many applications are likely to be in excess of a few 100 times. The new capability will of course stimulate as yet unforeseen activities through the proposed pilot studies. The project objectives are: (a) Provision of a shared UK resource for CW DNP-enhanced solid-state NMR at a fraction of the cost of the current less able commercial system and with performance better than the current state of the art. (b) The development of pulsed DNP techniques with higher sensitivity than the current CW methodologies. This is possible because the new source can provide microwave pulses as well as continuous output and would be a unique capability. (c) DNP studies utilizing polarization sources with short electron relaxation times. This is possible because of the high power and versatility of the new microwave source and should greatly enhance the range of applicability of the enhancement technique.

我们的愿景是创造一种核磁共振（NMR）光谱仪，它可以检测比最好的传统光谱仪弱数百倍的信号。NMR方法已被牢固确立为化学中的主要分析工具，对材料科学的表征越来越有影响力，并彻底改变了医学成像。尽管NMR取得了巨大的成功，但仍然存在通过提高该技术的灵敏度和速度来突破界限的巨大需求。这将使NMR能够用于研究广泛的问题，包括催化，电池和燃料电池，今天它的影响由于缺乏灵敏度而受到限制。此外，人们广泛认识到，结构信息是理解生物过程（例如蛋白质折叠，信号转导等）的关键。许多问题只有在核磁共振灵敏度显著提高的情况下才能解决。动态核极化（DNP）提供了一种令人兴奋的可能性，通过利用电子自旋固有的比核自旋大得多的极化（例如，13 C的极化约为2500倍）来大大提高NMR的灵敏度。沃里克的DNP基础设施由374万英镑的基础技术项目（EP/D 045967/1）资助。所开发的DNP系统的所有组件的功能都达到或超过其设计目标，但回旋管微波源除外，回旋管微波源不符合常规操作/开发所需的功率/稳定性要求。尽管如此，还是实现了大幅增强（60倍）。拟议的新的“交钥匙”微波源将提供显著增强的性能，比迄今使用的回旋管微波源更稳定、更灵活、更通用，并且运行成本显著降低。这将使继续快速发展和利用的DNP能力在沃里克。开发工作将与诺丁汉，圣安德鲁斯和南安普顿大学的研究人员合作完成，而增强的DNP能力将被更广泛的充满活力的英国MR社区所利用，他们将获得一种工具，可以对以前无法实现的系统进行研究。研究的影响将是显着的，因为在许多应用中的灵敏度增强可能超过几百倍。当然，新的能力将通过拟议的试点研究促进尚未预见的活动。 该项目的目标是：（a）为CW DNP增强型固态NMR提供联合王国的共享资源，其成本是目前能力较差的商业系统的一小部分，性能优于目前的最新技术水平。（B）开发灵敏度高于目前CW方法的脉冲DNP技术。这是可能的，因为新的源可以提供微波脉冲以及连续输出，这将是一个独特的能力。 (c)DNP研究利用极化源与短电子弛豫时间。这是可能的，因为新的微波源的高功率和多功能性，并应大大提高增强技术的适用范围。

项目成果

All-optical hyperpolarization of electron and nuclear spins in diamond

金刚石中电子和核自旋的全光超极化

• DOI: 10.1103/physrevb.96.054101
• 发表时间: 2017
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Green B