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2004

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Particle Physics: Lattice Window On Strong Force, I. Shipsey Jan 2004

Particle Physics: Lattice Window On Strong Force, I. Shipsey

Department of Physics and Astronomy Faculty Publications

No abstract provided.

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Electron Transparency, Ion Transparency And Ion Feedback Of A 3m Gem, P. S. Barbeau, J. Collar, J. Miyamoto, I. Shipsey Jan 2004

Electron Transparency, Ion Transparency And Ion Feedback Of A 3m Gem, P. S. Barbeau, J. Collar, J. Miyamoto, I. Shipsey

Department of Physics and Astronomy Faculty Publications

We report the first measurements of electron transparency, ion transparency and ion feedback of a mass produced 3M GEM. Our results indicate that a mass produced GEM and a CERN GEM have similar values of these three quantities. (C) 2004 Elsevier B.V. All rights reserved.

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Relativistic Jets, G. V. Bicknell, D. L. Jones, M. Lister Jan 2004

Relativistic Jets, G. V. Bicknell, D. L. Jones, M. Lister

Department of Physics and Astronomy Faculty Publications

Despite substantial observational and theoretical progress over many years, numerous key questions surrounding the topic of relativistic jets remain to be answered. In particular we still do not know how they are ejected from the supermassive black holes that are implicated in their production and we do not know how the ejection of matter at relativistic speeds is related to the properties of the parent galaxy. We are also just beginning to appreciate the role that relativistic jets play in the feedback loop between black holes and forming galaxies. The SKA will have a major impact in this field. The …

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Nonlinear Tapping Dynamics Of Multi-Walled Carbon Nanotube Tipped Atomic Force Microcantilevers, S. I. Lee, S. W. Howell, A. Raman, R. Reifenberger, C. V. Nguyen, M. Meyyappan Jan 2004

Nonlinear Tapping Dynamics Of Multi-Walled Carbon Nanotube Tipped Atomic Force Microcantilevers, S. I. Lee, S. W. Howell, A. Raman, R. Reifenberger, C. V. Nguyen, M. Meyyappan

Department of Physics and Astronomy Faculty Publications

The nonlinear dynamics of an atomic force microcantilever (AFM) with an attached multi-walled carbon nanotube (MWCNT) tip is investigated experimentally and theoretically. We present the experimental nonlinear frequency response of a MWCNT tipped microcantilever in the tapping mode. Several unusual features in the response distinguish it from those traditionally observed for conventional tips. The MWCNT tipped AFM probe is apparently immune to conventional imaging instabilities related to the coexistence of attractive and repulsive tapping regimes. A theoretical interaction model for the system using an Euler elastica MWCNT model is developed and found to predict several unusual features of the measured …

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The Cdf Run Iib Silicon Detector, M. Aoki, N. Bacchetta, S. Behari, D. Benjamin, D. Bisello, G. Bolla, D. Bortoletto, A. Burghard, G. Busetto, S. Cabrera, A. Canepa, G. Castro, G. Cardoso, M. Chertok, C. Ciobanu, G. Derylo, I. Fang, B. Flaugher, J. Freeman, L. Galtieri, J. Galyardt, M. Garcia-Sciveres, G. Giurgiu, I. Gorelov, C. Haber, K. Hara, M. Hoeferkamp, B. Holbrook, M. Hrycyk, T. Junk, S. Kim, K. Kobayashi, B. Krieger, M. Kruse, R. Lander, R. S. Lu, P. Lukens, L. Malferrari, C. Manea, A. Margotti, P. Maksimovic, P. Merkel, S. Moccia, I. Nakano, D. Naoumov, J. Novak, T. Okusawa, Y. Orlov, G. Pancaldi, D. Pantano, V. Pavlicek, D. Pellett, S. Seidel, F. Semeria, Y. Takei, R. Tanaka, Z. Wang, P. Watje, M. Weber, W. Wester, T. Wilkes, K. Yamamoto, W. Yao, W. Yao, S. Zimmermann, S. Zucchelli, A. Zucchini Jan 2004

The Cdf Run Iib Silicon Detector, M. Aoki, N. Bacchetta, S. Behari, D. Benjamin, D. Bisello, G. Bolla, D. Bortoletto, A. Burghard, G. Busetto, S. Cabrera, A. Canepa, G. Castro, G. Cardoso, M. Chertok, C. Ciobanu, G. Derylo, I. Fang, B. Flaugher, J. Freeman, L. Galtieri, J. Galyardt, M. Garcia-Sciveres, G. Giurgiu, I. Gorelov, C. Haber, K. Hara, M. Hoeferkamp, B. Holbrook, M. Hrycyk, T. Junk, S. Kim, K. Kobayashi, B. Krieger, M. Kruse, R. Lander, R. S. Lu, P. Lukens, L. Malferrari, C. Manea, A. Margotti, P. Maksimovic, P. Merkel, S. Moccia, I. Nakano, D. Naoumov, J. Novak, T. Okusawa, Y. Orlov, G. Pancaldi, D. Pantano, V. Pavlicek, D. Pellett, S. Seidel, F. Semeria, Y. Takei, R. Tanaka, Z. Wang, P. Watje, M. Weber, W. Wester, T. Wilkes, K. Yamamoto, W. Yao, W. Yao, S. Zimmermann, S. Zucchelli, A. Zucchini

Department of Physics and Astronomy Faculty Publications

Fermilab plans to deliver 5-15 fb(-1) of integrated luminosity to the CDF and D0 experiments. The current inner silicon detectors at CDF (SVXIIa and L00) will not tolerate the radiation dose associated with high-luminosity running and will need to be replaced. A new readout chip (SVX4) has been designed in radiation-hard 0.25 mum, CMOS technology. Single-sided sensors are arranged in a compact structure, called a stave, with integrated readout and cooling svstems. This paper describes the general design of the Run IIb system, testing results of prototype electrical components (staves), and prototype silicon sensor performance before and after irradiation. (C) …

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Tests Of Silicon Sensors For The Cms Pixel Detector, A. Dorokhov, C. Amsel, D. Bortoletto, V. Chiochia, L. Cremaldi, S. Cucciarelli, M. Konecki, K. Prokofiev, C. Regenfus, T. Rohe, D. Sanders, S. Son, T. Speer, M. Swartz Jan 2004

Tests Of Silicon Sensors For The Cms Pixel Detector, A. Dorokhov, C. Amsel, D. Bortoletto, V. Chiochia, L. Cremaldi, S. Cucciarelli, M. Konecki, K. Prokofiev, C. Regenfus, T. Rohe, D. Sanders, S. Son, T. Speer, M. Swartz

Department of Physics and Astronomy Faculty Publications

The tracking system of the CMS experiment, currently under construction at the Large Hadron Collider (LHC) at CERN (Geneva, Switzerland), will include a silicon pixel detector providing three spacial measurements in its final configuration for tracks produced in high-energy pp collisions. In this paper, we present the results of test beam measurements performed at CERN on irradiated silicon pixel sensors. Lorentz angle and charge collection efficiency were measured for two sensor designs and at various bias voltages. (C) 2004 Elsevier B.V. All rights reserved.

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Ion Source Modeling And Design At Prime Lab, G. S. Jackson, D. Elmore, M. Caffee, K. A. Mueller, B. De Bonte, P. Muzikar, B. Alexander Jan 2004

Ion Source Modeling And Design At Prime Lab, G. S. Jackson, D. Elmore, M. Caffee, K. A. Mueller, B. De Bonte, P. Muzikar, B. Alexander

Department of Physics and Astronomy Faculty Publications

The design and ion optics of a new high intensity cesium ion source and sample changer being built at PRIME Lab will be discussed. The ion source is based on the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory design and the sample changer is based on a sample changer developed at Chalk River Nuclear Laboratories in Canada. The ion optics are being modeled using Simion 7.0, which iteratively solves Laplaces' equation. Simion 7.0 does not require cylindrical symmetry so the effects of non-symmetric components, in particular the sample insertion rod and immersion lens can be explored. …

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The Earliest Shellmounds Of The Central-South Brazilian Coast, T. A. Lima, K. D. Macario, R. M. Anjos, P. R. S. Gomes, M. M. Coimbra, D. Elmore Jan 2004

The Earliest Shellmounds Of The Central-South Brazilian Coast, T. A. Lima, K. D. Macario, R. M. Anjos, P. R. S. Gomes, M. M. Coimbra, D. Elmore

Department of Physics and Astronomy Faculty Publications

This paper presents a new date for one of the oldest shellmounds of the central-south Brazilian coast. This date seems to confirm three previous results obtained from two other shellmounds in the same region and formerly seen as unreliable by the archaeological community. A charcoal sample from a coastal shellmound located in the state of Rio de Janeiro, Sambaqui do Algodao, was dated by C-14-AMS to 7860 +/- 80 years BP. Besides confirming the previous ones, this new date is pulling back, by some two thousand years the consensually accepted antiquity for, the initial settlement of the central-south Brazilian coast …

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Ams Radiocarbon Dating On Campos Basin, Southeast Brazilian Continental Slope, K. D. Macario, R. M. Anjos, P. R. S. Gomes, A. G. Figueiredo, C. L. De Souza, C. F. Barbosa, M. M. Coimbra, D. Elmore Jan 2004

Ams Radiocarbon Dating On Campos Basin, Southeast Brazilian Continental Slope, K. D. Macario, R. M. Anjos, P. R. S. Gomes, A. G. Figueiredo, C. L. De Souza, C. F. Barbosa, M. M. Coimbra, D. Elmore

Department of Physics and Astronomy Faculty Publications

We present results on radiocarbon dating of foraminifera shell samples, collected on the upper slope of Campos Basin, in Southern Brazil. This is the first time that the sedimentation rate of this area is measured with a fine scale (cm) stratigraphy. C-14 ages vary from (2560 +/- 80) years. BP at the top to (7260 +/- 80) years. BP at the bottom of the sediment column. The mean accumulation ratio for the whole column is (6.2 +/- 0.7) cm/kyears. (C) 2004 Elsevier B.V. All rights reserved.

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Intermittent Occupation Of The Sambaqui Builder Settlements In Rio De Janeiro State, Brazil, M. Barbosa, A. Buarque, M. D. Gaspar, K. D. Macario, R. M. Anjos, P. R. S. Gomes, M. M. Coimbra, D. Elmore Jan 2004

Intermittent Occupation Of The Sambaqui Builder Settlements In Rio De Janeiro State, Brazil, M. Barbosa, A. Buarque, M. D. Gaspar, K. D. Macario, R. M. Anjos, P. R. S. Gomes, M. M. Coimbra, D. Elmore

Department of Physics and Astronomy Faculty Publications

We study the time of settlement, period of occupation and the sociocultural system of the fishing-collecting groups, builders of huge shell and sand mounds found in the Brazilian coast. We present original results of four C-14 - AMS dates from the IBV4 archaeological site, one of the four sites of the Boa Vista group, located in Rio de Janeiro State, Brazil, and we analyze the occupation of the whole group. The results reaffirm the long occupation of populations in this region (similar to2400 yr). In this paper we complement the model proposed to this region, suggesting a discontinuous occupation of …

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A Test Of General Relativity: Estimating Ppn Parameters Gamma And Beta From Spacecraft Radiometric Tracking Data, R. S. Park, E. Fischbach, G. Giampieri, J. M. Longuski, D. J. Scheeres Jan 2004

A Test Of General Relativity: Estimating Ppn Parameters Gamma And Beta From Spacecraft Radiometric Tracking Data, R. S. Park, E. Fischbach, G. Giampieri, J. M. Longuski, D. J. Scheeres

Department of Physics and Astronomy Faculty Publications

The Theory of General Relativity (GR) can be tested by precisely measuring the shift of a spacecraft trajectory due to GR as it flies near the Sun. We apply the PPN metric to define the governing equations of motion for the spacecraft, and carry out a covariance analysis to estimate the Eddington-Robertson-Schiff parameters, gamma and 0, by simulating radiometric measurements of range, Very Long Baseline Interferometry, and Doppler. We show that the transient effect of GR over a short timespan is measurable to a significant level and that there is a potential for obtaining independent estimates of gamma and beta. …

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Search For Axion-Like Particles From The Sun In An Underground Negative-Ion Tpc, D. Naples, R. Ayad, G. Bonvincini, M. Katz-Hyman, J. Martoff, J. Miyamoto, V. Paolone, V. Savinov, I. Shipsey Jan 2004

Search For Axion-Like Particles From The Sun In An Underground Negative-Ion Tpc, D. Naples, R. Ayad, G. Bonvincini, M. Katz-Hyman, J. Martoff, J. Miyamoto, V. Paolone, V. Savinov, I. Shipsey

Department of Physics and Astronomy Faculty Publications

Axion-like particles produced in the sun with masses in the keV range have been proposed to explain several long-standing anomalies in astrophysical X-ray observations. The gravitationally bound massive axions could be observed decaying to two X-ray photons in an instrumented underground detector volume. We propose to use a 1.5m(3) Negative-Ion TPC instrumented with GEM/Micromegas pad readout to perform a sensitive search for keV range axions. The sensitivity of the proposed experiment will be five orders of magnitude below existing limits after one year of running.

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Spinning-Disk Self-Referencing Interferometry Of Antigen-Antibody Recognition, M. M. Varma, D. D. Nolte, H. D. Inerowicz, F. E. Regnier Jan 2004

Spinning-Disk Self-Referencing Interferometry Of Antigen-Antibody Recognition, M. M. Varma, D. D. Nolte, H. D. Inerowicz, F. E. Regnier

Department of Physics and Astronomy Faculty Publications

A gold ridge microstructure fabricated to a height of lambda/8 on a high-reflectivity substrate behaves as a wave-front-splitting self-referencing interferometer in phase quadrature when illuminated by a Gaussian laser beam and observed in the far field along the optic axis. When immuno-gammaglobulin (IgG) antibodies are selectively immobilized on the gold microstructure, they recognize and bind to a specific antigen, which shifts the relative optical phase of the interferometer and modifies the far-field diffracted intensity. We detect bound antigen interferometrically on spinning disks at a sampling rate of 100 kHz and verify the interferometric nature of the signal by using two …

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Domain Wall Resistance In Narrow Co Wires, B. Cetin, N. Giordano Jan 2004

Domain Wall Resistance In Narrow Co Wires, B. Cetin, N. Giordano

Department of Physics and Astronomy Faculty Publications

New results for the magnetoresistance of very narrow Co wires are presented. The resistance exhibits a complicated pattern of step-wise changes as the magnetization changes direction in response to a magnetic field. This behavior can be understood in terms of changes in the domain structure with field, combined with the anisotropic magnetoresistance. The results also suggest that the domain wall resistance is negative. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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Electron Transport And Magnetoresistance In Ferromagnetic Nanostructures, N. Giordano, B. Cetin Jan 2004

Electron Transport And Magnetoresistance In Ferromagnetic Nanostructures, N. Giordano, B. Cetin

Department of Physics and Astronomy Faculty Publications

Recent studies of very narrow Ni wires have shown that the resistance of a wire containing domain walls can be smaller than for a sample without walls; i.e., the domain wall resistance is effectively negative. In this paper we investigate the corresponding behavior of permalloy wires. For these wires the resistance decreases markedly during magnetization reversal. We show that this decrease is due to a combination of coherent rotation and a negative domain wall resistance. We are able to separate these two effects, and extract an estimate for the resistance of an individual domain wall. (C) 2004 WILEY-VCH Verlag GmbH …

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Meta-Analysis Of Two-Treatment Clinical Trials Including Both Continuous And Dichotomous Results, Charles F. Babbs Jan 2004

Meta-Analysis Of Two-Treatment Clinical Trials Including Both Continuous And Dichotomous Results, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

To expedite the timely creation of medical practice guidelines, a meta-analytic method was developed to combine of both dichotomous survival data and continuous physiologic data from multiple studies comparing the same innovative clinical intervention to standard care. The method is adapted for synthesis of small, early studies of novel treatments. An aggregate ratio, R*, of the observed treatment effect to a clinically optimal treatment effect for studies in a series is computed, and compared to the 95% confidence limit for R* under the null hypothesis. Weights assigned to each study may reflect its precision, quality, or clinical relevance. Input data …

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Compressor Rigid-Body Vibration Measurement, Wei Zhou, Floyd Gant Jan 2004

Compressor Rigid-Body Vibration Measurement, Wei Zhou, Floyd Gant

International Compressor Engineering Conference

No abstract provided.

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Boundary Layer Leakage Model, Jan Prins Jan 2004

Boundary Layer Leakage Model, Jan Prins

International Compressor Engineering Conference

No abstract provided.

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Measurement Of Oil Film Between Swash Plate And Shoe For Swash Plate Type Compressor, Tadashi Hotta, Takashi Inoue, Mikio Matsuda, Motohiko Ueda Jan 2004

Measurement Of Oil Film Between Swash Plate And Shoe For Swash Plate Type Compressor, Tadashi Hotta, Takashi Inoue, Mikio Matsuda, Motohiko Ueda

International Compressor Engineering Conference

No abstract provided.

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A New Device To Measure Instantaneous Swept Volume Of Reciprocating Machines/Compressors, K. Pannir Selvam, M. Udaya Kumar, C. Nageswara Rao Jan 2004

A New Device To Measure Instantaneous Swept Volume Of Reciprocating Machines/Compressors, K. Pannir Selvam, M. Udaya Kumar, C. Nageswara Rao

International Compressor Engineering Conference

No abstract provided.

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High Efficiency Pressure Oscillator For Low-Temperature Pulse Tube Cryocooler, Kyle B. Wilson, Reuven J. Unger Jan 2004

High Efficiency Pressure Oscillator For Low-Temperature Pulse Tube Cryocooler, Kyle B. Wilson, Reuven J. Unger

International Compressor Engineering Conference

No abstract provided.

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Design And Application Research On Digital Scroll Compressor In Air Conditioning System, Guang Hui Wu, Keiko Qi Wu Jan 2004

Design And Application Research On Digital Scroll Compressor In Air Conditioning System, Guang Hui Wu, Keiko Qi Wu

International Compressor Engineering Conference

No abstract provided.

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Three-Dimension Numerical Simulation Of Discharge Flow In A Scroll Air Compressor, Jian Mei Feng, Zong Chang Qu, Xin Wei Lin Jan 2004

Three-Dimension Numerical Simulation Of Discharge Flow In A Scroll Air Compressor, Jian Mei Feng, Zong Chang Qu, Xin Wei Lin

International Compressor Engineering Conference

No abstract provided.

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Extending The Operation Range Of Dry Screw Compressors By Cooling Their Rotors, Nikola Stosic, Ian K. Smith, Ahmed Kovacevic Jan 2004

Extending The Operation Range Of Dry Screw Compressors By Cooling Their Rotors, Nikola Stosic, Ian K. Smith, Ahmed Kovacevic

International Compressor Engineering Conference

No abstract provided.

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Theoretical And Experimental Investigation Of Compression Loads In Twin Screw Compressor, Hua Gen Wu, Yuan Ma, Zi Wen Xing Jan 2004

Theoretical And Experimental Investigation Of Compression Loads In Twin Screw Compressor, Hua Gen Wu, Yuan Ma, Zi Wen Xing

International Compressor Engineering Conference

No abstract provided.

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Numerical And Experimental Evaluation Of The Intake Manifold Layout On Cooling Capacity, Samuele Da Ros Jan 2004

Numerical And Experimental Evaluation Of The Intake Manifold Layout On Cooling Capacity, Samuele Da Ros

International Compressor Engineering Conference

No abstract provided.

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Flapper Valve Steels With High Performance, Guo Cai Chai, Gustaf Zetterholm, Bertil Walden Jan 2004

Flapper Valve Steels With High Performance, Guo Cai Chai, Gustaf Zetterholm, Bertil Walden

International Compressor Engineering Conference

No abstract provided.

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Single-Phase Flow And Heat Transport And Pumping Considerations In Microchannel Heat Sinks, S V. Garimella, Vishal Singhal Jan 2004

Single-Phase Flow And Heat Transport And Pumping Considerations In Microchannel Heat Sinks, S V. Garimella, Vishal Singhal

CTRC Research Publications

Microchannel heat sinks are widely regarded as being among the most effective heat removal techniques from space-constrained electronic devices. However, the fluid flow and heat transfer in microchannels is not fully understood. The pumping requirements for flow through microchannels are also very high, and none of the micropumps in the literature is truly suitable for this application. Results are reported from a wide-ranging research program being conducted on microchannel heat sinks and micropumps to understand fluid flow and heat transfer in microchannels and to identify pumping requirements and suitable mechanisms for pumping in microchannels. In particular, experiments have been performed …

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Microscale Pumping Technologies For Microchannel Cooling Systems, V. Singhal, S V. Garimella, A. Raman Jan 2004

Microscale Pumping Technologies For Microchannel Cooling Systems, V. Singhal, S V. Garimella, A. Raman

CTRC Research Publications

A review of the state of the art in micropumping technologies for driving fluid through microchannels is presented with a particular emphasis on small-scale cooling applications. An extensive variety of micropumping techniques developed over the past fifteen years in the literature is reviewed. The physical principles, engineering limitations, and advantages of approximately twenty different kinds of micropumps are reviewed. The available micropumping techniques are compared quantitatively, primarily in terms of the maximum achievable flow rate per unit cross-sectional area of the microchannel and the maximum achievable back pressure. A concise table is developed to facilitate the convenient comparison of the …

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Simulation Of Ion Generation And Breakdown In Atmospheric Air, W. Zhang, T. S. Fisher, S V. Garimella Jan 2004

Simulation Of Ion Generation And Breakdown In Atmospheric Air, W. Zhang, T. S. Fisher, S V. Garimella

CTRC Research Publications

Understanding of ion generation in air provides insights to several applications, such as gas sensors, electrohydrodynamic pumping, and air purification. In this paper, ion generation processes in atmospheric air are simulated using a particle-in-cell and Monte Carlo method with emphasis on the prediction of ion generation and breakdown characteristics in microscale gaps. The simulation results are validated through comparison to Townsend’s discharge theory and experiments. The significance of each relevant electron-molecule reaction is characterized to improve understanding of ion generation dynamics. Self-sustaining discharge and ionization are predicted under sufficient voltage bias, and the predicted trends of breakdown voltage are similar …

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