We show experimentally and describe theoretically how a conventional magnetic resonance Hahn echo sequence can lead to a self-stimulated pulse echo train when an inhomogeneously broadened spin ensemble is coupled to a resonator. Effective strong coupling between the subsystems assures that the first Hahn echo can act as a refocusing pulse on the spins, leading to self-stimulated secondary echoes. Within the framework of mean field theory, we show that this process can continue multiple times leading to a train of echoes. We introduce an analytical model that explains the shape of the first echo and numerical results that account well for the experimentally observed shape and strength of the echo train and provides insights into the collective effects involved.

中文翻译：

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不均匀加宽自旋组件的自激脉冲回波序列

我们通过实验显示并从理论上描述了当不均匀加宽的自旋系结耦合到谐振器时，常规的磁共振哈恩回波序列如何导致自激脉冲回波序列。子系统之间有效的强耦合确保了第一个Hahn回波可以充当自旋上的重新聚焦脉冲，从而导致自我激励的第二回波。在平均场理论的框架内，我们表明该过程可以持续多次，从而产生一系列回声。我们引入一个分析模型，该模型解释了第一回波的形状和数值结果，这些结果很好地说明了实验观察到的回波序列的形状和强度，并提供了对所涉及的集体效应的见解。