Nonlinear feature in the spatial uniformity of an atmospheric helium dielectric barrier discharge with the inter-dielectric gap width enlarged

摘要

Intuitively, when the breakdown voltage is satisfied, enlarging the inter-dielectric gap width (d_g) is prone to filamentary dielectric barrier discharges (DBDs) due to the lengthened electron migration path and the intensified electron cascade. In this letter, we report that in specific conditions, a larger d_g can also promote a homogeneous DBD. The calculated results from the two-dimensional fluid model of an atmospheric helium DBD reveal that the incomplete dissipation of glows (residual positive column) induced by the enlarged d_g poses an eraser-like role, wiping out the surface charges left behind by the former discharge. Thus, the so-called memory effect cannot be well established, and the uniform DBD ensues. An experiment with similar conditions and a simplified linear stability analysis qualitatively validate the calculated results. This work also provides sufficient feasibility of regulating discharge uniformity of DBDs through manipulating the dissipative characteristic, and some methods of tailoring waveform would be useful.