Automatic emissive probe apparatus for efficient plasma potential measurements

作者:Li, Jian-Quan; Lu, Wen-Qi*; Xu, Jun; Gao, Fei; Wang, You-Nian
来源:Review of Scientific Instruments, 2017, 88(11): 115106.
DOI:10.1063/1.4992017

摘要

The improved inflection point method of emissive probe is the most accurate method for plasma potential measurements, but its manual operation is quite cumbersome and time-consuming. This paper describes the design and test of an automatic emissive probe apparatus for efficient plasma potential measurements. The apparatus consists of a computer controlled data acquisition (DAQ) card, a working circuit composed of a biasing unit and a heating unit, as well as the emissive probe. The main feature of the apparatus is that both the biasing scan and the heating scan of the probe are controlled by the computer program through analog outputs of the DAQ card, which easily realizes the required timing between the biasing and heating scans of the probe. The apparatus can automatically execute the improved inflection point method of emissive probe and give the plasma potential result. The advantages of high-accuracy, high-efficiency, and durability of probe filament make the apparatus promising for extensive use in plasma potential measurements. Published by AIP Publishing.