带微处理器的再生式14N NQR谱仪

本文介绍一种用场效应管制成的限幅再生式¹⁴N NQR谱仪。这种谱仪的频率范围为(1-5) MHz,射频幅度(0.5-4) V_P-P,为了获得数字记录的NQR谱线,利用微处理器Z-80构成的数字相敏检波系统,把数字相敏检波系统接至信号处理通道,就构成一台带有微处理器的¹⁴N NQR谱仪。用它测定了乌洛托品(HMT)、亚硝酸钠和对位澳代苯胺等十多个含氯化合物在室温与77K时的¹⁴N NQR谱线。实验结果表明,用微处理器控制的NQR谱仪的信噪比是一般谱仪的两倍。此外,这种仪器也为进一步数据处理提供方便。

REGENERATIVE 14N NUCLEAR QUADRUPOLE RESONANCE SPECTROMETER WITH MICROPROCESSOR

An amplitude limited regenerative ¹⁴N NQR probe has been designed and built with field effect transistors. It has a frequency range of 1-5 MHz and a rf.amplitude range of 0.5-4 Vpp. In order to obtain a digital record system for NQR spectral lines, a microprocessor Z-80 is used to construct a phase sensitive detection system. By connecting this digital PSD system to the probe circuit through a signal processing channel, a regenerative ¹⁴N NQR spectrometer with microprocessor is constructed. The ¹⁴N NQR spectral lines of some compounds as hexa-methylenetetramine, sodium nitrite, urea etc. have been observed at room temperature and 77K with the spectrometer. The experiment results show that the s/n racio of NQR spectrometer with microprocessor is twice as large as one without microprocessor. Additionally, this instrument may provide a convenience for the further processing data.