【摘要】 LC回路是磁共振实验的关键信号检测单元,理解LC电路的幅频和相频特性是掌握核磁共振实验技术原理的重要环节.借助数字存储示波器实时测量信号参量功能,实验方案1提供了简易直观的谐振参量测量方法;利用双通道锁相放大器及其参考同步功能,实验方案2进一步展示了直观测量的教学可操作性.采用不同的幅值表示方法和相位差测量方法,既突出不同技术手段的原理共性,又体现近代物理实验课程承上启下的桥梁作用.更多还原

【Abstract】 LCcircuit is the key electric unit for signal detection in magnetic resonance experiment,and it is important to accurately understand its amplitude-frequency and phase-frequency characteristics for the comprehension of the principle of NMR technology.Using digital oscilloscope for real-time measurement of waveform parameters,experiment scheme 1 provided a simple and intuitive technique for measuring LCcircuit resonant characteristics,and experiment scheme 2 further demonstrated the operability of intuitive measurement method in teaching experiment by using dual-channel lock-in amplifier.The representation methods of waveform amplitude and phase difference in two schemes not only emphasized the commonness in experimental principle,but also reflected the bridge role of modern physics experiment in undergraduate course.更多还原