This review is inspired by the contributions from the University of Denver group to low-field EPR, in honor of Professor Gareth Eaton’s 80th birthday. The goal is to capture the spirit of innovation behind the body of work, especially as it pertains to development of new EPR techniques. The spirit of the DU EPR laboratory is one that never sought to limit what an EPR experiment could be, or how it could be applied. The most well-known example of this is the development and recent commercialization of rapid-scan EPR. Both of the Eatons have made it a point to remain knowledgeable on the newest developments in electronics and instrument design. To that end, our review touches on the use of miniaturized electronics and applications of single-board spectrometers based on software-defined radio (SDR) implementations and single-chip voltage-controlled oscillator (VCO) arrays. We also highlight several non-traditional approaches to the EPR experiment such as an EPR spectrometer with a “wand” form factor for analysis of the OxyChip, the EPR-MOUSE which enables non-destructive in situ analysis of many non-conforming samples, and interferometric EPR and frequency swept EPR as alternatives to classical high Q resonant structures.

中文翻译：

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无处不在的EPR

这篇综述的灵感来自丹佛大学小组对低场 EPR 的贡献，以纪念 Gareth Eaton 教授的 80 岁生日。目标是捕捉工作主体背后的创新精神，特别是因为它涉及新的 EPR 技术的开发。DU EPR 实验室的精神是从不试图限制 EPR 实验的内容或应用方式。最著名的例子是快速扫描 EPR 的开发和最近的商业化。伊顿夫妇都强调要了解电子和仪器设计的最新发展。为此，我们的评论涉及微型电子设备的使用以及基于软件定义无线电 (SDR) 实施和单芯片压控振荡器 (VCO) 阵列的单板光谱仪的应用。我们还重点介绍了 EPR 实验的几种非传统方法，例如用于分析 OxyChip 的具有“棒”形状因素的 EPR 光谱仪、能够对许多不合格样品进行非破坏性原位分析的 EPR-MOUSE，以及干涉式 EPR 和扫频 EPR 作为经典高 Q 谐振结构的替代品。