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 PW3: Laser Produced Plasmas Induced Breakdown and Applications of High Pressure Plasmas |
Hide Abstracts |
Chair: Matthew Goeckner, University of Texas at Dallas Room: Saratoga Hilton Ballroom 3 |
Wednesday, October 21, 2009 1:30PM - 2:00PM |
PW3.00001: Intense laser-driven cluster plasma production of fusion neutrons Invited Speaker: |
Wednesday, October 21, 2009 2:00PM - 2:15PM |
PW3.00002: Triggering Excimer Lasers by Photoionization from Corona Discharges Zhongmin Xiong, Thomas Duffey, Daniel Brown, Mark Kushner High repetition rate ArF (192 nm) excimer lasers are used for photolithography sources in microelectronics fabrication. In highly attaching gas mixtures, preionization is critical to obtaining stable, reproducible glow discharges. Photoionization from a separate corona discharge is one technique for preionization which triggers the subsequent electron avalanche between the main electrodes. Photoionization triggering of an ArF excimer laser sustained in multi-atmosphere Ne/Ar/F$_{2}$/Xe gas mixtures has been investigated using a 2-dimensional plasma hydrodynamics model including radiation transport. Continuity equations for charged and neutral species, and Poisson's equation are solved coincident with the electron temperature with transport coefficients obtained from solutions of Boltzmann's equation. Photoionizing radiation is produced by a surface discharge which propagates along a corona-bar located adjacent to the discharge electrodes. The consequences of pulse power waveform, corona bar location, capacitance and gas mixture on uniformity, symmetry and gain of the avalanche discharge will be discussed. [Preview Abstract] |
Wednesday, October 21, 2009 2:15PM - 2:30PM |
PW3.00003: Laser Induced Avalanche Ionization in Gases with REMPI or Femtosecond Pre-Ionization Mikhail Shneider, Richard Miles Results of a theoretical study regarding the minimal requirements for the first pre-ionizing pulse to initiate avalanche ionization and essential gas heating by the second pulse are presented. The problem of minimal gas component density for the REMPI (Resonanse Enhanced Multi-Photon Ionization) pre-ionization with subsequent avalanche ionization in a bulk gas is explored on the basis of the theoretical model developed for the Ar:Xe mixture, where during the initial portion of the pulse (3+1) REMPI of Ar atoms starts the ionization, which subsequently continues to grow with an avalanche in the buffer Xe gas [1]. Note, that this method of plasma generation at intensities much lower than required for breakdown is very close to one considered in ref. [2] with femtosecond pre-ionizing laser pulse. Scaling parameters for gas mixtures, laser pulse shape, focusing and frequency are studied. Possible applications for improving of the detection sensitivity of Radar REMPI diagnostic technique and laser initiated ignition are discussed. \\[4pt] 1. M.N. Shneider, Z.Zhang, R.B. Miles, J.Appl.Phys. \textbf{104}, 023302 (2008); 2. Z. Henis, G. Milikh, K. Papadopoulos, A. Zigler, J.Appl.Phys. \textbf{103}, 103111 (2008) [Preview Abstract] |
Wednesday, October 21, 2009 2:30PM - 2:45PM |
PW3.00004: X-Ray Induced Breakdown in Air with High Reduced Electric Field Robert Vidmar, Anusha Uppaluri An X-ray pulse was used to initiate breakdown of laboratory air at a high reduced electric field in a parallel plate geometry. The X-ray pulse is from 100 ns to several ms in duration and originates from a A 100 keV electron beam operating at a few mA. The X-ray pulse is shown to represent a volumetric ionization rate in air and the count rate from an X-ray detector is related to the volumetric ionization rate. An air-chemistry code is used to model the temporal change in electron density as a function of volumetric ionization rate and reduced electric field. Measurements of X-ray induced breakdown demonstrate the sensitivity of systems that operate with high reduced electric field to pulsed ionizing radiation. [Preview Abstract] |
Wednesday, October 21, 2009 2:45PM - 3:00PM |
PW3.00005: Diffuse coplanar surface barrier discharge -- basic properties and its application in surface treatment of nonwovens Dusan Kovacik, Jozef Rahel, Jana Kubincova, Anna Zahoranova, Mirko Cernak In recent years, low temperature atmospheric pressure plasma surface treatments have become a hot topic because of the potential of fast and efficient in-line processing fabrication without expensive vacuum equipment. A major problem of atmospheric pressure treatment in air is insufficient treatment uniformity because, particularly at the higher plasma power densities, the~air plasma has the tendency of filamentation and transition into an arc discharge. Diffuse coplanar surface barrier discharge (DCSBD) plasma source has been developed to overcome these problems. This type of discharge enables to generate macroscopically homogeneous thin ($\sim $ 0.3 mm) plasma layer with power density of some 100 W/cm$^{3}$ practically in any gas without admixture of He. It was found that the ambient air plasma of DCSBD is capable to make lightweight polypropylene nonwoven fabrics permanently hydrophilic, without any pinholing and with low power consumption of some 1~kWh/kg. [Preview Abstract] |
Wednesday, October 21, 2009 3:00PM - 3:15PM |
PW3.00006: Characterization of Atmospheric Pressure DC Negative Corona Discharges for Thin Film Deposition Dion Antao, Alexander Fridman, Bakhtier Farouk The applicability of DC corona discharges with their lower temperatures and uniformity is investigated for the deposition of thin films. The deposition is done at atmospheric pressure and room temperature, which lowers the facility cost as no vacuum or low pressure facilities are required and also enables continuous processing rather than batch processing. We report on our studies the operating regimes and the structures of DC negative corona discharges for a point to plate electrode configuration for thin film deposition. Traditionally DC coronas have been operated at extremely low currents. By modifying the circuit, we have been able to operate the DC corona at higher currents without breakdown. We operated the DC negative corona discharge in new regimes where a stable and diffuse glow has been observed near the anode surface. This diffuse glow is observed in air and methane containing discharges. The discharge is characterized by voltage-current diagnostics. Optical emission spectroscopy (OES) is used to obtain spatially resolved temperature measurements. The DC negative corona discharge has been observed to deposit films on the anode surface. The deposition of films and particles on the anode surface has introduced the possibility of using corona discharges as a novel method of materials deposition or surface modification at atmospheric pressure. [Preview Abstract] |
Wednesday, October 21, 2009 3:15PM - 3:30PM |
PW3.00007: Measured Current Distribution Functions Describing an Array of High Voltage Needles Operating In the Avalanche and Streamer Modes Erik Wemlinger, Patrick Pedrow, Manuel Garcia-Perez, Su Ha, Oscar Marin-Flores, Marvin Pitts It is hypothesized that cold plasma processing of small oxygenated molecules present in bio-oil will reduce coking in a catalytic steam reformer. The cold plasma reactor will be placed upstream of the reformer and will consist of an array of needles held at a DC voltage in the 5-10 kV range. The distribution of current pulses on each needle will be measured for gas mixtures consisting of varying amounts of argon, water, methanol, oxygen, and carbon dioxide. The small oxygenated hydrocarbon molecules from bio-oil can be reduced to hydrogen and synthesis gas by the catalytic steam reformer. However, the steam reforming of these oxygenated hydrocarbon molecules has a high tendency of coke formation. In this work, catalyst coking will be reduced by integrating the atmospheric pressure cold plasma reactor. Studying how distribution functions for elements in a small array ($<$ 10 needles) ``interact'' will facilitate design of larger needle arrays that can be used for the commercial processing of biofuels. [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. |
© 2024 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