用于等离子体电位测量的电容探针和发射探针

PLASMA POTENTIAL MEASUREMENT WITH EMISSIVE PROBE AND CAPACITY PROBE

本文给出了发射探针和电容探针测量等离子体电位的实验和方法。发射探针采用直流功率加热，并在较强电子发射条件下运行（Ｉ_（ｅ０）／Ｉ_（ｅ０）＞１）。电容探针表面二次电子发射系数δ≥１。本文对发射探针的电子发射性能、工作电流、电容探针的输入、输出电压关系进行了标定实验。得到了电容探针的校准系数分别为３×１０（－３）、５×１０（－４）。实验给出了ＭＭ－４会切中心等离子体电位Ｖ_（ｐ４）＝－８２±９－１２２±１２Ｖ；ＭＭ－４Ｕ东、西会切中心等离子体电位分别为Ｖ_（Ｐ４ｕ１）＝－５２．９±３．２Ｖ，Ｖ_（Ｐ４ｕ２）＝－６２±３．２Ｖ。

Experiments and methods for measuring plasma potential with emissive probe and capacity probe are described. The emissive probe was heated by DC power supply and operated in strong emission ( I(e0)/I(c0)>1).The secondary emission coefficient σ of the capacity probe satisfies σ≥1.The experiments have been made for determining the emissive characteristics.the working current of the emissive probe, and the ratio of input to output voltage of the capacity probe. The calibrated factors are 3 ×10(-3), 5 ×10(-4),respectively.The plasma potential at the core of the MM4 plasma is V(P4)=-82±9-122±12V,while those at two points (The east core and the west core) of the MM-4U are V=52.9±3.2V and V,=-62±3.2V, respectively.