A5077850920- Plasma Diagnostics and Applications
- Plasma Applications and Diagnostics
- Semiconductor materials and devices
- Metal and Thin Film Mechanics
- Ion-surface interactions and analysis
- Electrohydrodynamics and Fluid Dynamics
- Diamond and Carbon-based Materials Research
- Dust and Plasma Wave Phenomena
- Copper Interconnects and Reliability
- Surface Modification and Superhydrophobicity
- Laser-induced spectroscopy and plasma
- Mass Spectrometry Techniques and Applications
- Catalytic Processes in Materials Science
- Plasma and Flow Control in Aerodynamics
- Particle accelerators and beam dynamics
- Advancements in Photolithography Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Atomic and Molecular Physics
- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Graphene research and applications
- Advancements in Semiconductor Devices and Circuit Design
- Silicon Nanostructures and Photoluminescence
- nanoparticles nucleation surface interactions
- Chemical and Physical Studies
Princeton University
2020-2025
Princeton Plasma Physics Laboratory
2020-2025
Columbia River Inter-Tribal Fish Commission
2024
University of California, Berkeley
2012-2021
New York University
2020
JPS Health Network
2018
Meijo University
2016
Australian National University
2016
Lancaster University
2016
Lancaster City Council
2016
Reactive oxygen species (ROS) and the closely related reactive nitrogen (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These also central players what is sometimes referred to as 'redox' or oxidation–reduction biology. Oxidation–reduction biochemistry fundamental all aerobic ROS RNS perhaps best known disease-associated agents, implicated diabetes, cancer, heart lung disease, autoimmune disease a host other maladies including...
Journal of Physics D: Applied published the first Plasma Roadmap in 2012 consisting individual perspectives 16 leading experts various sub-fields low temperature plasma science and technology. The 2017 is update a planned series periodic updates Roadmap. continuously growing interdisciplinary nature field its equally broad range applications are making it increasingly difficult to identify major challenges that encompass all many applications. This intellectual diversity ultimately strength...
Cold atmospheric plasma (CAP) treatment of living tissues becomes a popular topic in modern physics and medical sciences. The is capable bacterial inactivation noninflammatory tissue modification, which makes it an attractive tool for wound healing the skin diseases dental caries. There are still many open issues with regard to mechanisms action on bacteria mammalian cells tissues, both from biological physical perspective. For example, chemistry CAP exact roles various constituents not yet...
Abstract We present a numerical model of surface microdischarge (SMD) in humid air at atmospheric pressure. Our includes over 50 species and 600 elementary reactions consists two, coupled well-mixed regions: discharge layer with both charged neutral an afterglow region consisting only species. Multiple time steps employed our enable capturing rapid dynamic behaviour the as well relatively slow diffusion reaction afterglow. A short duration, high electric field is assumed to be excited 10 kHz...
Indirect air dielectric barrier discharge in close proximity to water creates an acidified, nitrogen-oxide containing solution known as plasma-activated (PAW), which remains antibacterial for several days. Suspensions of E. coli were exposed PAW either 15 min or 3 h over a 7-day period after generation. Both exposure times yielded initial activity corresponding ∼5-log reduction cell viability, decreased at differing rates 7 days negligible and 2.4-log exposures, respectively. The remained pH...
A continuum model of direct current (dc) and 13.56-MHz radio-frequency (RF) discharges in a parallel-plate configuration is presented. The consists equations for electron ion continuity, Poisson's equation the self-consistent electric field, an energy. are solved single set conditions comparison made between structure dc RF discharge. One major structural differences emergence, under conditions, large conduction currents quasi-neutral region. This results substantially higher heating region...
Abstract The 2022 Roadmap is the next update in series of Plasma Roadmaps published by Journal Physics D with intent to identify important outstanding challenges field low-temperature plasma (LTP) physics and technology. format same as previous representing visions 41 leading experts 21 countries five continents various sub-fields LTP science In recognition evolution field, several new topics have been introduced or given more prominence. These emphasis highlight increased interests...
Abstract Cold atmospheric plasmas (CAP) formed in air generate reactive oxygen and nitrogen species (RONS). RONS are biologically therapeutically active agents experimental evidence suggests that shrink tumors by increasing oxidative nitrosative stress on neoplastic tissue. Most mainline anti‐cancer therapies – including ionizing radiation chemotherapies also operate primarily via this pro‐oxidant, oxidative, mechanism. The main disadvantage of these conventional is the development...
Ambient-condition air plasma produced by indirect dielectric barrier discharges can rapidly disinfect aqueous solutions contaminated with bacteria and other microorganisms. In this study, we measured key chemical species in plasma-treated the associated antimicrobial effect for varying discharge power densities, exposure times, buffer components medium. The chemistry corresponded to chemistry, observed a transition composition from ozone mode nitrogen oxides as density increased....
A ‘‘reference cell’’ for generating radio-frequency (rf) glow discharges in gases at a frequency of 13.56 MHz is described. The reference cell provides an experimental platform comparing plasma measurements carried out common reactor geometry by different groups, thereby enhancing the transfer knowledge and insight gained rf discharge studies. results performing ostensibly identical on six these cells five laboratories are analyzed discussed. Measurements were made voltage current...
Mathematical models of dc glow discharges sustained by electrons emitted the cathode and accelerated into fall must take account highly nonequilibrium nature these fast electrons. However, electric field profile through discharge is determined mainly distribution ions slow In this paper we explore three methods to for fast, electrons: single-beam method, multibeam particle (Monte Carlo) simulations. Ions cold are treated using equations change assuming collisionally dominated motion (i.e.,...
Particle-in-cell (PIC) simulations are used to study the structure of radio-frequency (RF) glow discharges in helium between parallel-plate electrodes. The authors have examined a range conditions and report on variety observed phenomena. Comparisons experiment analytical models made, when possible. differences which secondary electrons play key role sustaining discharge those unimportant three cases illustrate importance discharge-sustaining mechanisms. Electron-energy distributions found...
Collisionless orbit theory is used to model isolated particles in low-pressure discharges with and without the presence of negative ions. The key results are as follows: (1) Debye–Hückel works well for approximating potential profile around particle, (2) size sheath particle determined by a Debye length that from linearizing Poisson–Vlasov equation. These valid long ratio radius small mean free path small.
The gas‐phase kinetics and plasma chemistry of high density oxygen discharges are studied. A self‐consistent spatially averaged model is developed to determine positive ion, negative electron densities, ground state metastable free radical temperature as functions gas pressure, microwave input power, cylindrical source diameter length. For an cyclotron resonance discharge, the reduction in radial transport due confining magnetic field also modeled. kinetic scheme includes excitation,...
We present the transient, dynamic behavior of ozone production in surface micro-discharge (SMD) plasma ambient air. Ultraviolet absorption spectroscopy at 254 nm was used to measure time development density a confined volume. observed that increases monotonically over 1000 ppm for least few minutes when input power is lower than ∼0.1 W/cm2. Interestingly, higher W/cm2, starts decrease tens seconds constant density, showing peak density. A model calculation suggests depletion caused by...
A key need for the development and testing of models suitable chemically active, low pressure plasmas is detailed comparisons between model predictions experimental measurements. In this paper, a two-dimensional, axisymmetric fluid an inductively coupled plasma described, are compared to measurements P. A. Miller, G. Hebner, K. E. Greenberg, D. Pochan, B. Aragon [J. Res. Natl. Inst. Stand. Technol. 100, 427 (1995)] electron density, temperature, potential. Comparisons were made in argon...
Low pressure, non-equilibrium, weakly to partially ionized gas discharge plasmas are used for a variety of surface materials processing applications. The most extensive applications in microelectronics manufacturing, where plasma sputtering, etching, stripping, cleaning and film deposition play key roles this growing industry. Up 30% all process steps integrated circuit manufacture involve low pressure one way or another. rapid pace product technological change industry, coupled with the...
Particles in glow discharges are charged negatively and therefore often suspended electrostatically since the plasma potential is usually more positive than of surfaces bounding plasma. However, addition to responding electrostatic gravitational forces, particles sensitive forces associated with gradients neutral gas temperature. A series experiments were performed varying temperature water circulated through planar, parallel electrodes. When present discharge, they move away from a heated...
Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources reactive species for the emerging field plasma biotechnology because their convenience and ability to operate at ambient conditions. One biological application ambient-air is microbial disinfection, plasmas decontaminate both solid surfaces liquid volumes has been thoroughly established in literature. However, mechanism disinfection which most strongly correlate with antimicrobial effects still not...
Using a one-way coupled model of neutral gas flow and plasma dynamics we report mechanism to explain the ring-shaped emission pattern that has been observed experimentally in bullets at atmospheric pressure. We solve fluid with local field approximation one-dimensional cylindrical coordinates, corresponding cross-section bullet. Pulselike uniform electric is assumed be applied perpendicular simulation domain. Time spatially resolved spectroscopic measurements support results.