中国物理B ›› 2003, Vol. 12 ›› Issue (2): 198-203.doi: 10.1088/1009-1963/12/2/314
林揆训, 林璇英, 池凌飞, 余楚迎, 姚若河, 余云鹏
Lin Kui-Xun (林揆训), Lin Xuan-Ying (林璇英), Chi Ling-Fei (池凌飞), Yu Chu-Ying (余楚迎), Yao Ruo-He (姚若河), Yu Yun-Peng (余云鹏)
摘要: Electron energy distribution function (EEDF) is a key parameter of plasmas, which is directly proportional to the second derivative of the probe I-V characteristics. Because of an amplifying effect of unavoidable noises in the experimental probe I-V curves during the derivation process, the experimental I-V curves should be smoothed before performing the numerical derivation. This paper investigates the effect of adjustable factors used in the smoothing process on the deduced second derivative of the I-V curves, and an optimum group of the adjustable factors is selected to make the rms deviation of the smoothed I-V curves from the measured curves less than 1%. A simple differentiation circuit is designed and used to measure the EEDF parameter straightforwardly. It is the first time, so far as we know, to measure the EEDF parameters simultaneously by means of both numerical and circuit derivative methods under the same discharge conditions and on the same discharge equipment. The deviation between two groups of mean electron energy E and electron density n_e obtained by the above different methods is within about 7%. This apparently improves the reliability of the measurements of the EEDF parameters.
中图分类号: (High-frequency and RF discharges)