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论文类型：期刊论文

发表时间：2011-12-01

发表刊物：PHYSICS OF PLASMAS

收录刊物：Scopus、SCIE、EI

卷号：18

期号：12

ISSN号：1070-664X

关键字：helium; high-frequency discharges; numerical analysis; plasma simulation

摘要：Experiments observed that the pulse duty cycle has effects on the plasma homogeneity in pulse-modulated radio frequency (rf) discharges. In this paper, pulse-modulated rf (13.56 MHz) helium discharges are theoretically investigated using a two dimensional fluid model. With the pulse period being fixed to 15 mu s, it is found that when the pulse-on duration is over 4 mu s, i.e., the duty cycle is larger than approximately 27%, the discharge transits from an inhomogeneous to a homogeneous mode in every specific part of each pulse cycle under currently-used simulation parameters. More quantitative analysis shows that the discharge becomes more homogeneous as the duty cycle is increased but does not reach complete homogeneity. Possible reasons for the homogeneity improvement are discussed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3671967]