One-dimensional modeling of ac noble gas discharges with insulated electrodes
- Univ. of Toledo, OH (United States)
The presence of a dielectric film on the electrode surfaces of a capacitively coupled gas discharge imparts a very strong influence on the dynamics of the glow. As the discharge progresses, the plasma current deposits electrons and ions onto the anode and cathode surfaces, respectively. The resulting surface charge densities act to oppose the applied potential, reducing the net potential across the gap and causing the discharge to extinguish. The duration of the discharge and the voltage transferred to the dielectric is related to the strength of the applied potential relative to the threshold potential which is determined by the Townsend firing condition, {gamma}(exp({alpha}L)-l)=l. Here {alpha} and {gamma} are the first and second Townsend co-efficients and L is the gap distance. If the polarity of the applied potential is subsequently reversed, the potential on the dielectric due to the surface charges will add to the applied potential. This will result in a stronger discharge (but in the opposite direction) or will enable an equal discharge to be produced with a more modest applied potential. Essentially, the dielectric coatings on the electrodes serve to extinguish the discharge and provide some {open_quote}memory{close_quote} which will affect the firing of each subsequent pulse. A practical application of this phenomena is found in ac-plasma, display technology. In this paper, we will explore the dynamics of an ac-PDP cell of pure helium, using a completely self-contained theory. We generate all relevant electron-driven rates and transport parameters from an exact-numerical Boltzmann solver, and self-consistently solve the Poisson and electron/ion/neutral fluid equations in one dimension. Rates from the Boltzmann equation are incorporated through a local-field approximation.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 213043
- Report Number(s):
- CONF-950749-; TRN: 96:010192
- Resource Relation:
- Conference: 22. international conference on phenomena in ionized gases, Hoboken, NJ (United States), 31 Jul - 4 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of XXII International conference on phenomena in ionized gases. Contributed papers 4; Becker, K.H.; Carr, W.E.; Kunhardt, E.E. [eds.]; PB: 256 p.
- Country of Publication:
- United States
- Language:
- English
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