简化三探针方法用于瞬态等离子体诊断的局限性  

Limitations of simplified triple-probe method for instantaneous plasma diagnostic experiments

作　　者：陆文琪[1] 汤元真 LU Wenqi;TANG Yuanzhen(School of Physics,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学物理学院,辽宁大连116024

出　　处：《物理实验》2023年第7期8-12,共5页Physics Experimentation

基　　金：国家自然科学基金面上项目(No.11975070)。

摘　　要：为展示一些瞬态等离子体诊断实验中采用基于悬浮电位测量的简化三探针方法而产生误差的问题,本文利用示波器对脉冲微波电子回旋共振(ECR)等离子体的悬浮电位进行测量,并将结果与时间分辨单探针的测量值进行比较,说明了利用示波器测量悬浮电位产生误差的原因,即存在示波器测量悬浮电位所固有的探针对地有限电阻与“悬浮”要求之间的矛盾以及探针对地高阻抗和测量系统快速响应之间的矛盾.三探针诊断对比实验展示了简化三探针方法由于悬浮电位测量导致误差,且对诊断结果带来显著影响,因此准确的瞬态等离子体诊断应当采用标准的双偏置三探针方法.In order to exhibit the problem that existed in some instantaneous plasma diagnostic experiments using the triple-probe method based on floating-potential-measurement,the floating potential of a pulsed microwave electron cyclotron resonance(ECR)plasma was measured with an oscilloscope,which was compared with that obtained by a time-resolved single-probe.The results revealed that the reason for the errors in the floating-potential-measurements by an oscilloscope was the contradiction between the floating requirement and the limited probe-ground resistance,and that between the high probe-ground impedance and the rapid response of the measurement system.Further triple-probe diagnostic experiments showed that the errors mainly caused by the floating-potential-measurement would bring a significant influence to the diagnostic results.It could be concluded that for instantaneous plasma diagnostics,the standard dual-biased triple-probe method should be adopted.

关 键 词：简化三探针 瞬态等离子体 悬浮电位 测量时间分辨率 

分 类 号：O539[理学—等离子体物理]