Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, 2021 6(th) Street SE, Minneapolis, MN 55455, USA.
Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, 2021 6(th) Street SE, Minneapolis, MN 55455, USA.
J Magn Reson. 2020 Dec;321:106855. doi: 10.1016/j.jmr.2020.106855. Epub 2020 Oct 22.
When viewed in a rotating frame of reference, a transverse-plane radiofrequency (RF) field manifests as a longitudinal field component called the fictitious field. By modulating the RF field and thus the fictitious field, detectable longitudinal magnetization patterns have previously been shown to be measurable. By combining fictitious-field modulation and longitudinal detection, here we demonstrate EPR spectroscopy and one-dimensional imaging in a custom-built longitudinal detection system operating at an ultra-low frequency (24 MHz) for detecting electron spins with short (nanoseconds) relaxation times. Simultaneous transmit and receive with low transmitter leakage level (80 dB isolation) is also demonstrated.
在旋转参考系中观察时，横平面射频 (RF) 场表现为称为虚拟场的纵向场分量。通过调制 RF 场，从而调制虚拟场，以前已经证明可以检测到可检测的纵向磁化模式。通过结合虚拟场调制和纵向检测，我们在这里展示了在定制的纵向检测系统中进行的 EPR 光谱学和一维成像，该系统以超低频 (24 MHz) 运行，用于检测具有短 (纳秒) 弛豫时间的电子自旋。同时还展示了具有低发射器泄漏水平 (80 dB 隔离) 的发送和接收。
