Impact of the characteristic impedance of coaxial lines on the sensitivity of a 750-MHz electronically tunable EPR resonator
Impact of the characteristic impedance of coaxial lines on the sensitivity of a 750-MHz electronically tunable EPR resonator
复制标题
同轴线特性阻抗对 750 MHz 电子可调谐 EPR 谐振器灵敏度的影响
DOI：
10.1007/s00723-018-1001-6
复制
发表时间：
2018
影响因子：
1
通讯作者：
H. Hirata
中科院分区：
文献类型：
--
作者：
R. Nakaoka;D. A. Komarov;S. Matsumoto;H. Hirata
研究了一种750 MHz电子调谐谐振腔的电子顺磁共振（EPR）信号检测灵敏度。利用三维微波场和微波电路模拟器计算了50 Ω和100 Ω同轴耦合线谐振器的射频磁场转换效率。基于模拟结果，两个可调谐谐振器的物理构造和比较的EPR信号灵敏度方面使用硝酰基自由基溶液。虽然具有100 Ω同轴线的谐振器提供了14%的高信号强度，但其信噪比低于具有50 Ω线的谐振器。为了证明所构建的可调谐谐振器用于EPR成像实验的能力，将硝酰基自由基溶液和荷瘤小鼠的腿可视化。
A 750-MHz electronically tunable resonator was investigated in terms of the sensitivity of electron paramagnetic resonance (EPR) signal detection. The conversion efficiency of the radio-frequency magnetic field was calculated for resonators with 50- and 100-Ω coaxial coupling lines using three-dimensional (3D) microwave field and microwave circuit simulators. Based on the simulation results, two tunable resonators were physically constructed and compared in terms of EPR signal sensitivity using a nitroxyl radical solution. While the resonator with 100-Ω coaxial lines provided 14% greater signal intensity, its signal-to-noise ratio was lower than that of the resonator with 50-Ω lines. To demonstrate the capability of the constructed tunable resonator for EPR imaging experiments, a solution of nitroxyl radical and the leg of a tumor-bearing mouse were visualized.