Similarity laws (SL) are essential for correlating the characteristics of plasmas at different dimensional scales, which have been validated for radio frequency (rf) discharges at low pressure but under limited conditions. In this work, we evaluate the effects of nonlinear collisions (e.g. stepwise ionization) on the similarity properties in capacitive rf discharges in argon across a wide range of pressure regimes via fully kinetic particle-in-cell simulations. The SL scalings of fundamental discharge parameters, e.g. the electron power absorption and electron energy probability function, are examined with and without nonlinear collisions, respectively. Without the nonlinear collisions, the similarity scalings are found to be rigorously valid. When the nonlinear collisions are considered, the similarity properties in rf discharges still exist approximately, which indicates that the violations caused by the nonlinear collisions are still minor in the studied cases. The reasons for the effectiveness of SL scalings with nonlinear collision processes are also discussed. The results from this study confirmed the validity of similarity transformations with more complex reaction kinetics, which may promote the applicability of the SL scalings for the design and fabrications of plasma devices.
Yang, Dong, et al. "Similarity properties in capacitive radio frequency plasmas with nonlinear collision processes." Plasma Sources Science and Technology, vol. 30, no. 11, Nov. 2021. https://doi.org/10.1088/1361-6595/ac2f0a
Yang, Dong, Fu, Yangyang, Zheng, Bocong, et al., "Similarity properties in capacitive radio frequency plasmas with nonlinear collision processes," Plasma Sources Science and Technology 30, no. 11 (2021), https://doi.org/10.1088/1361-6595/ac2f0a
@article{osti_1979311,
author = {Yang, Dong and Fu, Yangyang and Zheng, Bocong and Wang, Huihui and Fan, Qi Hua and Zou, Xiaobing and Wang, Xinxin and Verboncoeur, John P.},
title = {Similarity properties in capacitive radio frequency plasmas with nonlinear collision processes},
annote = {Abstract Similarity laws (SL) are essential for correlating the characteristics of plasmas at different dimensional scales, which have been validated for radio frequency (rf) discharges at low pressure but under limited conditions. In this work, we evaluate the effects of nonlinear collisions (e.g. stepwise ionization) on the similarity properties in capacitive rf discharges in argon across a wide range of pressure regimes via fully kinetic particle-in-cell simulations. The SL scalings of fundamental discharge parameters, e.g. the electron power absorption and electron energy probability function, are examined with and without nonlinear collisions, respectively. Without the nonlinear collisions, the similarity scalings are found to be rigorously valid. When the nonlinear collisions are considered, the similarity properties in rf discharges still exist approximately, which indicates that the violations caused by the nonlinear collisions are still minor in the studied cases. The reasons for the effectiveness of SL scalings with nonlinear collision processes are also discussed. The results from this study confirmed the validity of similarity transformations with more complex reaction kinetics, which may promote the applicability of the SL scalings for the design and fabrications of plasma devices.},
doi = {10.1088/1361-6595/ac2f0a},
url = {https://www.osti.gov/biblio/1979311},
journal = {Plasma Sources Science and Technology},
issn = {ISSN 0963-0252},
number = {11},
volume = {30},
place = {United States},
publisher = {IOP Publishing},
year = {2021},
month = {11}}