Effect of surface protrusion on plasma sheath properties in atmospheric microdischarges
Abstract
The electric field enhancement due to the presence of cathode surface protrusion is investigated in atmospheric microdischarges with the goal of identifying the plasma sheath properties (such as cathode sheath thickness and electric field distortion). The electric field enhancement caused by surface protrusion is examined by adjusting the aspect ratio and the protrusion size. It is found that the cathode electric field enhancement depends strongly (weakly) on the aspect ratio (size) of the protrusion when it is much smaller than the discharge gap distance. In particular, the axial electric field in both vacuum and discharges becomes nonlinear with the protrusion on the cathode. The cathode sheath thicknesses obtained by two different methods are compared. With the same axial (or radial) protrusion dimension, increasing the aspect ratio will result in a significant decrease in the sheath thickness, whereas increasing the axial protrusion size with an unchanged aspect ratio will only lead to a slight decrease in the sheath thickness. The results contribute to predicting the relative plasma sheath properties from the geometrical parameter of the surface protrusion in atmospheric microdischarges.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 01, 2018
- Source ID
- 10.1063/1.5011768
Entities
People
- Andrew J. Christlieb
- John Verboncoeur
- Peng Zhang
- Xinxin Wang
- Yangyang Fu
Organizations
- Air Force Office of Scientific Research
- Michigan State University
- National Natural Science Foundation of China
- Tsinghua University
- United States Department of Energy