Bulletin of the American Physical Society
62nd Annual Gaseous Electronics Conference
Volume 54, Number 12
Tuesday–Friday, October 20–23, 2009; Saratoga Springs, New York
Session XF1: Microplasmas |
Hide Abstracts |
Chair: Paul McGuire, University of Ulster Room: Saratoga Hilton Ballroom 1 |
Friday, October 23, 2009 10:00AM - 10:30AM |
XF1.00001: Large Arrays of Microplasmas: Science, Applications, and the Road Ahead Invited Speaker: The science and technology of microcavity plasma devices has advanced rapidly over the past 5 years. Large arrays, comprising $>10^5$ devices, have been realized and electron number densities as large as $>10^{17}$ cm$^{-3}$ have been generated reproducibly on a pulsed basis. This presentation will review briefly the characteristics of microplasmas generated within cavities as small as 10 $\mu$m. A view of future scientific opportunities will be offered and the recent discovery of a hybrid plasma/semiconductor device, based upon coupling of electron-hole and gas phase plasmas, will be reported. [Preview Abstract] |
Friday, October 23, 2009 10:30AM - 10:45AM |
XF1.00002: Comparison of Silicon- and Polymer-based Micro-structured Atmospheric Pressure Plasma Arrays Henrik Boettner, Arthur Greb, Volker Schulz-von der Gathen, J\"org Winter We report on phase, space and spectrally resolved optical emission spectroscopic combined with electrical measurements on micro-structured atmospheric pressure plasma arrays. These arrays have confining structures in the range of several 10 $\mu $m and consist of typically 50x50 single discharges. Two different types of arrays are investigated. One is made up of a Ni-grid and inverse pyramidical structures etched in a Si-wafer as electrodes, separated by an insulator and each coated with Si-Ni. The second type consists of small capillaries etched in a polymer arranged as a grid. The polymer is coated with ITO electrodes. Both types are typically operated in rare gas at atmospheric pressure and frequencies in the range of several kHz. The devices are compared in their individual and collective discharge behavior. We study the influence of excitation function shape and frequency on the development of pulse bursts. This determines the on-time and hence the emission efficiency of the devices. Furthermore, excitation waves running across the arrays are observed, indicating cross-talk between individual pixels. First measurements on basic energy transport systems and excitation dynamics leading to this phenomenon have been performed. This work is funded by DFG project SCHU-2353/1. [Preview Abstract] |
Friday, October 23, 2009 10:45AM - 11:00AM |
XF1.00003: Electrical characterization of Direct Current atmospheric pressure micro discharges using Radio frequency signal in Argon Monali Mandra, Lawrence Overzet, Matthew Goeckner, Thierry Dufour, Remi Dussart, Philippe Lefaucheux Parallel Micro Hollow Cathode discharges (MHCD) are fabricated in a sandwich structure as Nickel-Alumina-Nickel. 500 um thick, 3.5 inch alumina wafers are used as the dielectric between the 8 um thick Nickel films. A single micro cavity of 180 um diameter is laser drilled. An L-C tank circuit along with a matching network is used to super impose a small RF signal on the DC ignited micro discharge as a diagnostic tool. A simple equivalent circuit is used for analyzing the various key plasma parameters such as electron density, cathode sheath thickness, cathode sheath area and ion current density in the sheath by measuring the RF-impedance and capacitance of the micro-plasma. Reasonable results were obtained for argon DC micro-plasmas over a wide pressure range from 300 Torr to 1000 Torr and varying DC current. The sheath widths are found to vary slowly with pressure and are constant with DC current, while the electron density and sheath area both increase with current. These along with the IV characteristic of single hole MHCD are all consistent with what is expected for normal glow discharge regime. The technique and analysis results for argon micro-plasmas will be presented. [Preview Abstract] |
Friday, October 23, 2009 11:00AM - 11:15AM |
XF1.00004: Modeling cathode boundary layer discharges E. Munoz-Serrano, J.P. Boeuf, L.C. Pitchford A Cathode Boundary Layer Discharge or CBL (Schoenbach, et al Plasma Sources Sci. Technol. 13, 177,2004) is an electrode/dielectric/electrode sandwich with a central hole pierced through the dielectric and one of the electrodes (the anode). Thus, the cathode surface area available to the discharge is limited by the annular dielectric, and the discharge operates in an abnormal glow mode with a positive V-I characteristic at higher current. Using a two-dimensional fluid model, we have studied the electrical properties of CBLs in argon at 100 and 400 torr pressure. The spatial profiles of charged particle and metastable densities, potential, and gas temperature, as well as calculated V-I characteristics will be shown for a range of conditions for a 800 micron hole diameter. One interesting result (anticipated in the work of Belostotskiy, et al, Plasma Sources Sci. Technol 17, 045018, 2008) is that there is a sharp increase in the slope of the V-I characteristic when gas heating is taken into account. This current limiting effect is not observed when the discharge is able to expand on the outer surface of the cathode as in the case of the MicroHollow Cathode Discharge (MHCD) configuration, for example. [Preview Abstract] |
Friday, October 23, 2009 11:15AM - 11:30AM |
XF1.00005: Coupled Mode Theory: A Path to Stable Microplasma Arrays Jeffrey Hopwood, Zhibo Zhang Atmospheric plasmas are challenging to generate across large dimensions due to a plethora of instabilities. Recently, however, microplasmas have been generated with electron densities approaching that of a plasma torch, but with gas temperatures near room temperature. The possibility of treating large areas of low-temperature material with dense, atmospheric pressure plasma is attractive, but requires that microplasma concepts be dimensionally scaled. In this work we demonstrate that strong coupling among arrays of microwave resonators allows for the production of 1-dimensional arrays of microplasmas. Each microplasma is sustained at the tip of a quarter-wave microstrip resonator which is driven at 400 MHz. This individual resonator stabilizes the 200 micron plasma against the glow-to-arc transition. Linear arrays of identical quarter-wave resonators naturally redistribute energy among each other according to coupled mode theory. This redistribution of energy allows us to sustain multiple microplasmas by simply supplying power to just one resonator in an array. In the paper, we show that coupled mode theory, 3-D electromagnetic simulations, and experimental optical emission from microplasma arrays of 5 and 16 resonators are in close agreement. [Preview Abstract] |
Friday, October 23, 2009 11:30AM - 11:45AM |
XF1.00006: Properties of Dielectric-Barrier-Free Atmospheric Pressure Micro Plasma Driven by Sub-Micro Second DC Pulse Voltage Hae June Lee, Chang Seung Ha, Ho-Jun Lee, Dong-Hyun Kim An atmospheric pressure micro-plasma driven by a DC pulse has been developed. This device consists of He flowing two dielectric-free metal electrodes with a voltage pulse shorter than 500 ns, thus it maintains a glow discharge. Spatio-temporal measurements by the optical emission spectroscopy show that the change of partialpressure ratio between He and N$_2$ is one of the most important factors affecting the discharge properties. The enhancement of the oxygen emissions for higher He flow rate mainly comes during afterglow, which suggests that the dissociative excitation of O$_2$ by He metastable states is critical process for effective generation of oxygen radicals. As an alternative of atmospheric pressure micro plasma jet based on the dielectric barrier discharge or rf- driven micro plasma, dc pulse driven dielectric barrier-free configuration discharge can be used as an efficient and cost effective source for bio-medical and material processing applications. [Preview Abstract] |
Friday, October 23, 2009 11:45AM - 12:00PM |
XF1.00007: Atmospheric pressure direct current micro glow discharge simulation: Effects of the external circuit Tanvir Farouk, Bakhtier Farouk The effect of the external circuit on discharge conditions are not explicitly considered in most modeling studies of thermal and non-thermal plasma discharges. In this study, we investigate the effects of including the external circuit on simulation results of atmospheric pressure micro discharges. Two-dimensional simulations of DC atmospheric pressure micro glow discharges were conducted using a hybrid model. The discharge model is coupled to an external circuit model enabling to study the effect of the external circuit parameter. Simulation results were first obtained by excluding the external circuit. When included, the external circuit consisted of a ballast resistance and a parasitic capacitance connected in series and parallel in respect to the discharge. Simulations were conducted over a broad discharge current range (varying ballast resistance) and also for varying parasitic capacitance. For large ballast resistance the discharge was found to operate in the Townsend regime as a dark discharge. At smaller ballast resistance the discharge showed \textit{`normal'} glow like characteristics. The simulations further indicated that for higher values of the parasitic capacitance the discharge even with a DC power supply was self oscillatory; indicating some unstable regime. The predicted results were found to be in agreement with experimental observations. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2025 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700