Electron heating and mode transition in dual frequency atmospheric pressure argon dielectric barrier discharge

Z L Zhang,J W M Lim,X N Zhang,B H Jiang,Q Y Nie

doi:10.1063/1.5000044

Z L Zhang, J W M Lim + Show 3 more

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https://doi.org/10.1063/1.5000044

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Abstract

Plasma ionization, excitation, mode transitions and associated electron heating mechanisms in atmospheric pressure dielectric barrier discharges (DBD) driven by dual radio frequency sources are investigated in this paper. The electrons are found to be heated mainly by the high frequency component in the plasma bulk when discharged in α mode. On the contrary, the low frequency component is primarily responsible for heating in the sheath which is caused by intense motion in the sheath. It was also found that variation of the lower frequency component ratio could effectively modulate the electron energy distribution as determined from time averaged EEDF. The results above have demonstrated that the independent control of plasma parameters via non-linear synergistic effect between the dual frequency sources can be achieved through reasonable selection of processing parameters.

Highlights

Non-equilibrium cold atmospheric plasmas (CAPs) have been widely investigated in numerous research institutes, and implemented in various industries due to their potentially profound impact on applied technology.[1,2,3,4,5] The benefits from utilizing CAPs include the generation of a high density plasma at room temperature which reduces the need for expensive vacuum and confinement facilities
This is largely because the physical and chemical properties critically depend on the dynamics of power dissipation and electron heating mechanisms, whereby the plasma parameters are highly susceptible and influenced primarily by instabilities, mode transitions and associated aAuthor to whom correspondence should be addressed
It is necessary to gain insight into the electron heating mechanisms in such atmospheric pressure dielectric barrier discharge (DBD) system to bridge the gap in theoretical understanding for specific and targeted application-focused studies

Summary

Introduction

Non-equilibrium cold atmospheric plasmas (CAPs) have been widely investigated in numerous research institutes, and implemented in various industries due to their potentially profound impact on applied technology.[1,2,3,4,5] The benefits from utilizing CAPs include the generation of a high density plasma at room temperature which reduces the need for expensive vacuum and confinement facilities. From figures 1(a)–1(e) we can see the discharge transits from α to γ mode through the markedly distinct evolution of the electron impact ionization rate with increasing the component of low frequency applied in the overall ratio.

Results

Conclusion