SF_(6)替代气体电子群参数的脉冲汤逊法测量研究

Study on Measurements of Swarm Parameters in SF_(6) Alternative Gases by Pulsed Townsend Method

为了测量SF_(6)替代气体的电子群参数,设计并搭建高精度的脉冲汤逊实验平台。根据脉冲汤逊法的原理,可以获得所测气体的有效电离速率系数、电子漂移速度和密度归一化纵向电子扩散系数。详细介绍所搭建的实验平台、实验方法以及用于数据处理的物理模型。基于设计搭建的实验平台和建立的参数获取方法,选取纯CO(2)在10k Pa下,约化电场强度(E/N)在0~130Td范围内开展实验测量,并将所测得的实验结果与求解Boltzmann方程计算结果和文献中的实验结果进行对比。实验成功地测量了CO(2)气体的有效电离速率系数、电子漂移速度和扩散系数,并且根据所测得的有效电离速率系数,可以确定CO(2)的临界击穿电场为(86±1)Td。通过对比发现,该文的实验结果与参考值有很好的一致性,并且对实验可能存在的误差也做出了相应的分析。此外,还对新型环保气体C_(4)F_(7)N进行测试,测量了其在100Pa下的有效电离速率系数。该文设计搭建的脉冲汤逊实验平台以及建立的参数获取方法将用于各种新型环保缘气体的电子群参数测量和绝缘性能评估,为进一步深入研究新型环保气体放电机理提供关键基础参数。

In order to investigate the swarm parameters of SF_(6) alternative gases, a high-precision pulsed Townsend experimental setup was built. With the principle of pulsed Townsend measurements, the swarm parameters, including the effective ionization rate coefficient, electron drift velocity and density-normalized longitudinal diffusion coefficient, could be obtained. The experimental setup and measurement methods were described in detail, as well as the swarm model for signal analysis. The setup and methods were verified with measurement in CO_(2) at 10 kPa, with the(E/N) range from 0 to 130 Td. The present results were compared with experimental reference data, and the swarm parameters calculated by a Boltzmann equation solver. The effective ionization rate coefficient, electron drift velocity and density-normalized longitudinal diffusion coefficient in CO(2) were successfully measured, and the critical electric field strength(E/N)cr for CO(2) was obtained to be(86±1) Td according to the measured effective ionization rate coefficient. The good agreement was found for the effective ionization rate coefficient between the present data with references. Meanwhile, good agreement could be found when comparing the experimental results with reference data, and the possible error were analyzed. Furthermore, some tests on pure C_(4)F_(7)N were done, obtaining its effective ionization rate coefficient at 100 Pa. The experimental apparatus and methods will be used to measure swarm parameters and evaluate the dielectric strength of SF6 alternative gases, providing significant fundamental data for further study on their discharge mechanism.