Two-dimensional simulation of ac-driven microplasmas confined to 100-300 {mu}m diameter cylindrical microcavities in dielectric barrier devices

Journal Article · Fri Dec 15 00:00:00 EST 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2398024· OSTI ID:20884933

Seo, Jeong Hyun; Eden, J Gary ^[1]

---

1. Laboratory for Optical Physics and Engineering, Department of Electrical and Computer Engineering, University of Illinois, 1406 West Green Street, Urbana, Illinois 61801 (United States)

Cylindrical microcavity plasma devices with diameters (D) in the 100-300 {mu}m range and a dielectric barrier structure similar to that described by Park et al. [J. Appl. Phys. 99, 026107 (2006)] for Al/Al{sub 2}O{sub 3} devices have been investigated numerically. A two-dimensional fluid simulation of microplasmas in Ne/7% Xe gas mixtures with pD values (where p is the total gas pressure) in the 3-9 Torr cm interval yields the temporal history of the spatially resolved electron and ion number densities in response to a 250 kHz bipolar excitation wave form. Calculations show two distinct regions of plasma development, along the microcavity axis and near the wall, each of which dominates the plasma characteristics in separate pD regions. For low pD values (<4 Torr cm), the negative glow produced at the cavity wall extends to the microcavity axis which, in combination with the strong axial electric field, produces an intense glow discharge on axis. For 4(less-or-similar sign)pD(less-or-similar sign)6 Torr cm, a weakened axial discharge is observed early in the life of the plasma but the radial variation of the electron density flattens. Further increases in the gas pressure (to the largest pD values investigated, 6-9 Torr cm) result in the retreat of the negative glow to the vicinity of the microcavity wall, thereby producing a diffuse but annular discharge. Even at the higher pD values, the axial discharge appears to facilitate ignition of the negative glow. The predictions of the simulations are consistent with the behavior of Al/Al{sub 2}O{sub 3} microplasma devices for which D=100-300 {mu}m.

• OSTI ID: 20884933
• Journal Information: Journal of Applied Physics, Vol. 100, Issue 12; Other Information: DOI: 10.1063/1.2398024; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM
ALUMINIUM OXIDES
CYLINDRICAL CONFIGURATION
DIELECTRIC MATERIALS
ELECTRIC FIELDS
ELECTRON DENSITY
ELECTRONS
GLOW DISCHARGES
MIXTURES
NEON
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA SIMULATION
TWO-DIMENSIONAL CALCULATIONS
WALL EFFECTS
WAVE FORMS
XENON