Abstract:

A new phase comparator technique, called FFT, was introduced and applied successfully to the calculation of electron density ne for the interferometer data on the HL-2A tokamak. After calculating a great number of the experimental data and comparing the results with another two old methods: hardware and conventional software, the correctness and reliability of FFT have been affirmed. FFT can not only give the electron density curve in truth, but also overcome the jump and excursion of density curve at a certain extent. Whereas, without real-time calculation is its own defect.

Key words: Phase comparator, FFT, Laser interferometer, Electron density

摘要：

介绍了一种新的相位比较技术——傅里叶变换法，并将其成功地应用到了HL-2A装置激光干涉测量等离子体电子密度的计算中。通过对大量实验数据的脱机计算后，将其结果与硬件比较方法、传统软件计算方法的结果进行了对比，证实了傅里叶变换相位比较技术的正确性和可靠性；它不仅能够真实地反映电子密度变化行为，还能一定程度上改善密度曲线起始时刻不归零和跳变行为，但不能够实时计算电子密度是该方法存在的不足。

关键词: 相位比较, 傅里叶变换法, 激光干涉测量, 电子密度