Volume 96, Issue 4, 15 August 2004
Index of content:
- PLASMAS AND ELECTRICAL DISCHARGES (PACS 51-52)
96(2004); http://dx.doi.org/10.1063/1.1769599View Description Hide Description
The neutral and positive ion species of two inductively coupled plasma(ICP)discharges, operated with low-pressure argon and sulfur hexafluoride gas mixtures, are studied with optical emission and mass spectrometry. Similar discharges sustained in the two ICPs show significantly different species. The spectra of the hemispherical ICP suggest nearly pure discharges. The spectra of the planar ICP reveal many species containing silicon and oxygen, from etching of the quartzdielectric.Etch rate measurements support these observations.
96(2004); http://dx.doi.org/10.1063/1.1769607View Description Hide Description
We investigate the interaction between electromagnetic (EM) fields and a hydrogen plasma in a resonance-type microwaveplasma reactor, by combining an elementary theoretical analysis and a self-consistent two-dimensional numerical model. We show that the EM fields in the reactor are strongly modified by the presence of plasma; due to absorption the standing wave patterns of the field intensity are less pronounced. In turn, the electric field controls the electron temperature and the plasma formation. For typical conditions (field frequency , gas pressure, gas temperature) it is not just the electric field that controls the plasma, but rather the reduced electric field, i.e., the ratio of electric field strength to gas particle density. We show that the dependence of the reduced field on the gas temperature has a reinforcing effect on plasma formation and may cause jumps in the spatial plasma configuration as a function of power or pressure. We also show that the plasma size is limited by the skin effect.
Simulations studies on influence of concentration on discharge of alternating current plasma display panels in mixture96(2004); http://dx.doi.org/10.1063/1.1773920View Description Hide Description
With recent experiments to add gas to the conventional discharge gas mixture for high luminous efficiency plasma display panels, we have performed simulations on a coplanar structured alternating current plasma display panel sustained in the gas mixture, by using the two-dimensional fluid model simulator. As the concentration increases, luminance and luminous efficiencies increase but power consumption decreases, which agrees well with the recent experimental findings. atoms increase the number of in the excited state and thus, the dimer emission is increased while the resonant line is reduced with the content. As a result, the total vacuum ultraviolet emission is increased and higher luminance and higher luminous efficiency can be obtained. The enhanced mobilities of the ions in the gas mixture by adding gas to the mixture also play an important role in increasing luminous efficiency.
Two-dimensional space-time-resolved emission spectroscopy on atmospheric pressure glows in helium with impurities96(2004); http://dx.doi.org/10.1063/1.1773923View Description Hide Description
The time dependence of the spectral emission of an atmospheric pressureglow discharge in helium with impurities has been studied with a two-dimensional spatial resolution. Emissions from and are used to qualitatively map the distributions of high- and low-energy electrons, respectively. The emission from provides qualitative information about the relative spatial distribution of metastable atoms within the discharge gap. The results demonstrate a radial spreading of the discharge during the current pulse as well as the formation of a ringlike, radially propagating cathode layer late in the current pulse.