Capital Award for Core Equipment 2022/23, National Research Facility for Electron Paramagnetic Resonance Spectroscopy

2022/23年度核心设备资本奖，国家电子顺磁共振波谱研究装置

• 批准号: EP/X034623/1
• 负责人: David Collison
• 金额: $ 60.51万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX034623%2F1
• 关键词: Capital; Award; Core; Equipment; 2022

Electron Paramagnetic Resonance (EPR) spectroscopy, also known as Electron Spin Resonance (ESR), is possibly the most powerful technique for characterisation of paramagnetic materials, i.e. that contain unpaired electrons. Unpaired electrons give rise to the magnetic and electronic properties of materials and often govern reactivity when present, hence understanding their environment and behaviour is important. Paramagnets are ubiquitous from biological processes to magnetic materials; hence EPR is an essential tool in physics, chemistry, materials and biological sciences. The EPSRC funds a National Research Facility (NRF) for EPR, located in the Photon Science Institute (PSI) at The University of Manchester (UoM), providing access to state-of-the art experimental techniques and expertise for the UK academic community. Crudely, there are two ways to do EPR spectroscopy: continuous wave (cw) EPR and pulsed EPR, which give complementary information. Pulsed EPR is a much higher resolution technique (allowing measurement of much weaker interactions involving the unpaired electron) and also gives access to time-resolved information. However, such experiments can require access to very low temperatures (<10 K) otherwise signal response may be non-existent or data collection very slow, requiring long data collection to get acceptable signal-to-noise (e.g. due to low paramagnet concentration). It is common for an experiment on a single sample to last a week of continuous measurement. As a consequence, the three pulsed EPR spectrometers that the EPR NRF currently runs are by far and away the most oversubscribed pieces of instrumentation. Two of those spectrometers have cooling systems that give base temperature of ca. 2 K and can be remotely monitored and controlled, but the third only reaches 10 K and requires manual control. Allied to a forthcoming upgrade, all pulsed EPR frequencies will have the same sample temperature control, thereby maximising flexibility and throughput across four frequency bands (two per spectrometer platform): X-/Q-, Q-/S- and X-/L-bands, noting that Q- and X-band are most requested frequencies by the user community. There has been a large increase in the interest in and use of optically excited samples monitored by EPR spectroscopy, which are primarily serviced by either pulsed or transient EPR methods. Like many pulsed experiments, data collection can be slow, and the inclusion of pulsed light excitation into the microwave (and sometimes radiofrequency) pulse sequences lengthens measurement time further. Installing a fast, high power, tunable laser will increase capacity and efficiency of these optical experiments. In conjunction with our slower, lower power tunable laser, the EPR spectrometers will be able to deliver 'two colour' experiments, for which there is also growing interest.The extension to cooling and optical excitation capability will increase the capacity for pulsed EPR for all users of the NRF across the UK, including ECRs and doctoral students, and the new capabilities will widen the user base. To contact the National EPR Facility and Service, please email: [e-mail] and web-site: https://www.chemistry.manchester.ac.uk/epr/

电子顺磁共振 (EPR) 光谱，也称为电子自旋共振 (ESR)，可能是表征顺磁性材料（即包含不成对电子的顺磁性材料）的最强大的技术。不成对的电子会产生材料的磁性和电子特性，并且在存在时通常控制反应性，因此了解它们的环境和行为非常重要。从生物过程到磁性材料，顺磁体无处不在。因此，EPR 是物理、化学、材料和生物科学中的重要工具。 EPSRC 资助位于曼彻斯特大学 (UoM) 光子科学研究所 (PSI) 的 EPR 国家研究设施 (NRF)，为英国学术界提供最先进的实验技术和专业知识。粗略地说，有两种方法可以进行 EPR 光谱：连续波 (cw) EPR 和脉冲 EPR，它们提供了互补的信息。脉冲 EPR 是一种分辨率更高的技术（可以测量涉及不成对电子的较弱相互作用），并且还可以获取时间分辨信息。然而，此类实验可能需要非常低的温度 (<10 K)，否则信号响应可能不存在或数据收集非常缓慢，需要长时间的数据收集才能获得可接受的信噪比（例如，由于顺磁体浓度低） 。对单个样品进行的实验持续一周的连续测量是很常见的。因此，EPR NRF 目前运行的三台脉冲 EPR 光谱仪无疑是超额订购最多的仪器。其中两个光谱仪具有冷却系统，可提供约 100°C 的基础温度。 2K，可以远程监控，但第三种只有10K，需要手动控制。与即将推出的升级相结合，所有脉冲 EPR 频率都将具有相同的样品温度控制，从而最大限度地提高四个频段（每个光谱仪平台两个）的灵活性和吞吐量：X-/Q-、Q-/S- 和 X-/L - 频段，指出 Q 频段和 X 频段是用户群体最需要的频率。人们对 EPR 光谱监测光激发样品的兴趣和使用大大增加，这些样品主要由脉冲或瞬态 EPR 方法提供服务。与许多脉冲实验一样，数据收集可能很慢，并且将脉冲光激发纳入微波（有时是射频）脉冲序列会进一步延长测量时间。安装快速、高功率、可调谐激光器将提高这些光学实验的容量和效率。与我们速度较慢、功率较低的可调谐激光器相结合，EPR 光谱仪将能够进行“双色”实验，人们对此也越来越感兴趣。冷却和光学激发能力的扩展将提高脉冲 EPR 的能力，适用于所有领域。英国各地 NRF 的用户，包括 ECR 和博士生，新功能将扩大用户群。如需联系国家 EPR 设施和服务，请发送电子邮件至：[e-mail] 和网站：https://www.chemistry.manchester.ac.uk/epr/