A5030507867- Plasma Diagnostics and Applications
- Dust and Plasma Wave Phenomena
- Plasma Applications and Diagnostics
- Electrohydrodynamics and Fluid Dynamics
- Electrostatic Discharge in Electronics
- Metal and Thin Film Mechanics
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum, superfluid, helium dynamics
- Ionosphere and magnetosphere dynamics
- Laser-induced spectroscopy and plasma
- Laser Design and Applications
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- Particle accelerators and beam dynamics
- Semiconductor materials and devices
- Gas Sensing Nanomaterials and Sensors
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Diamond and Carbon-based Materials Research
- High voltage insulation and dielectric phenomena
- Theoretical and Computational Physics
- GaN-based semiconductor devices and materials
- Physics of Superconductivity and Magnetism
- Advanced Chemical Physics Studies
- Material Dynamics and Properties
HUN-REN Wigner Research Centre for Physics
2016-2025
Institute for Solid State Physics and Optics
2015-2024
Osaka University
2018-2024
Al-Farabi Kazakh National University
2017-2021
Dalian University of Technology
2017-2021
Ruhr University Bochum
2017-2021
Hungarian Academy of Sciences
2010-2019
Boston College
2008-2017
University of California, San Diego
2016
Institute for Literary Studies
2016
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...
Properties of two-dimensional strongly coupled Yukawa systems are explored through molecular dynamics simulations. An effective coupling coefficient gamma* for the liquid phase is introduced on basis constancy first peak amplitude pair-correlation functions. Thermodynamic quantities calculated from function. The solid-liquid transition system investigated analysis bond-angular order parameter. static structure function satisfies consistency relation, attesting to reliability computational...
Unlike α- and γ-mode operation, electrons accelerated by strong drift ambipolar electric fields in the plasma bulk at sheath edges are found to dominate ionization strongly electronegative discharges. These caused a low conductivity local maxima of electron density edges, respectively. This drift-ambipolar mode is investigated kinetic particle simulations, experimental phase-resolved optical emission spectroscopy, an analytical model CF(4). Mode transitions induced voltage pressure...
This paper illustrates the application of particle simulation methods for description low-pressure discharges: Townsend discharges, cathode fall dominated dc glows and capacitively coupled radiofrequency discharges. The spatially and/or temporally varying electric field presence boundaries (e.g. electrodes) in these plasma sources induce a non-hydrodynamic (or non-equilibrium) transport some types charged species, particularly electrons. Particle-based provide, even under non-equilibrium...
A combined theoretical and molecular dynamics (MD) simulation study of the collective modes their dispersion in a two-dimensional Yukawa system strongly coupled liquid state is presented. The analysis relies upon quasilocalized charge approximation; MD generates static pair correlation functions dynamical current-current spectra.
Recently a novel approach for achieving separate control of ion flux and energy in capacitively coupled radio frequency (CCRF) discharges based on the electrical asymmetry effect (EAE) was proposed (Heil et al 2008 J. Phys. D: Appl. 41 165202). If applied, temporally symmetric voltage waveform contains an even harmonic fundamental frequency, sheaths front two electrodes are necessarily asymmetric. A dc self-bias develops is function phase angle between driving voltages. By tuning phase,...
In dusty (complex) plasmas, containing mesoscopic charged grains, the grain-grain interaction in many cases can be well described through a Yukawa potential.In this Review we summarize basics of computational and theoretical approaches capable describing many-particle systems liquid solid phases discuss properties dynamical density current correlation spectra three-and two-dimensional strongly coupled systems, generated by molecular dynamics simulations.We show details ω(k) dispersion...
Two fundamentally different types of dual-frequency (DF) capacitively coupled radio frequency discharges can be used for plasma processing applications to realize separate control the ion mean energy, ⟨Ei⟩, and flux, Γi, at substrate surface: (i) classical operated substantially frequencies, where low- high-frequency voltage amplitudes, ϕlf ϕhf, are ⟨Ei⟩ respectively; (ii) electrically asymmetric (EA) a fundamental its second harmonic with fixed, but adjustable phase shift between driving θ....
Benchmarking is generally accepted as an important element in demonstrating the correctness of computer simulations. In modern sense, a benchmark simulation result that has evidence correctness, accompanied by estimates relevant errors, and which can thus be used basis for judging accuracy efficiency other codes. this paper, we present four cases related to capacitively coupled discharges. These benchmarks prescribe all physical numerical parameters. We have simulated conditions using five...
The electrical asymmetry effect (EAE) in geometrically symmetric capacitively coupled radio frequency discharges operated at multiple consecutive harmonics is investigated by a particle-in-cell (PIC) simulation and an analytical model. model based on the original EAE model, which extended taking into account floating potentials, voltage drop across plasma bulk, symmetry parameter resulting from PIC simulation. Compared with electrically asymmetric dual-frequency we find that (i)...
In low temperature plasmas, the interaction of electrons with electric field is an important current research topic that relevant for many applications. Particularly, in pressure regime (≤10 Pa), can traverse a distance may be comparable to reactor dimensions without any collisions. This causes “nonlocal,” dynamics which results complicated space- and time-dependence strong anisotropy distribution function. Capacitively coupled radio frequency (CCRF) discharges, operate this regime, exhibit...
The effect of changing the driving frequency on plasma density and electron dynamics in a capacitive radio-frequency argon operated at low pressures few Pa is investigated by particle-in-cell/Monte-Carlo collision simulations analytical modeling. In contrast to previous assumptions, does not follow quadratic dependence this non-local collisionless regime. Instead, step-like increase distinct observed. Based an power balance model, combination with detailed analysis kinetics, jump found be...
Power absorption by electrons from the space- and time-dependent electric field represents basic sustaining mechanism of all radio-frequency driven plasmas. This complex phenomenon has attracted significant attention. However, most theories models are, so far, only able to account for part relevant mechanisms. The aim this work is present an in-depth analysis power electrons, via use a moment Boltzmann equation without any ad-hoc assumptions. analysis, which input quantities are taken...
Abstract Particle based simulations are indispensable tools for numerical studies of charged particle swarms and low-temperature plasma sources. The main advantage such approaches is that they do not require any assumptions regarding the shape velocity/energy distribution function (VDF/EDF), but provide these basic quantities kinetic theory as a result computations. Additionally, can provide, e.g. transport coefficients, under arbitrary time space dependence electric/magnetic fields. For...
We report a series of complex (dusty) plasma experiments, aimed at the study detailed time evolution recrystallization process following rapid quench two-dimensional dust liquid. The experiments were accompanied by large-scale (million-particle) molecular dynamics simulations, assuming Yukawa-type interparticle interaction. Both experiment and simulation show ∝t(α) (power-law) dependence linear crystallite domain size as measured bond-order correlation length, translational dislocation...
Various types of capacitively coupled radio frequency (CCRF) discharges are frequently used for different applications ranging from chip and solar cell manufacturing to the creation biocompatible surfaces. In many these electron heating dynamics not fully understood. A powerful diagnostic study in CCRF is phase resolved optical emission spectroscopy (PROES). It non-intrusive provides access highly energetic electrons, which sustain discharge via ionization, with high spatial temporal...
Capacitive radio frequency (RF) discharge plasmas have been serving hi-tech industry (e.g. chip and solar cell manufacturing, realization of biocompatible surfaces) for several years. Nonetheless, their complex modes operation are not fully understood represent topics high interest. The understanding these phenomena is aided by modern diagnostic techniques computer simulations. From the industrial point view control ion properties particular interest; possibilities independent flux energy...
Electric field reversals in single and dual-frequency capacitively coupled radio frequency discharges are investigated the collisionless (1Pa) collisonal (65Pa) regimes. Phase resolved optical emission spectroscopy is used to measure excitation of neutral background gas caused by reversal during sheath collapse. The regime experimentally asymmetric neon hydrogen operated at 13.56MHz a GEC reference cell. collisional symmetric industrial discharge 1.937 27.118MHz. resulting spatio-temporal...
Dual-frequency capacitive discharges are used to separately control the mean ion energy, ε¯ion, and flux, Γion, at electrodes. We study effect of secondary electrons on this separate in argon driven 2+27 MHz different pressures using Particle Cell simulations. For yield γ≈0, Γion decreases as a function low frequency voltage amplitude due coupling, while it increases high γ effective multiplication inside sheaths. Therefore, is strongly limited. ε¯ion with γ, which might allow an situ...
At low pressures, nonlinear self-excited plasma series resonance (PSR) oscillations are known to drastically enhance electron heating in geometrically asymmetric capacitively coupled radio frequency discharges by (NERH). Here we demonstrate via particle-in-cell simulations that high-frequency PSR can also be excited symmetric if the driving voltage waveform makes discharge electrically asymmetric. This achieved a dual-frequency (f+2f) excitation, when and NERH turned on off depending...
We present an analytical model to describe capacitively coupled radio-frequency (CCRF) discharges and the electrical asymmetry effect (EAE) based on non-linearity of boundary sheaths. The describes various discharge types, e.g. single multi-frequency as well geometrically symmetric asymmetric discharges. It yields simple expressions for important plasma parameters such dc self-bias, uncompensated charge in both sheaths, current power dissipated electrons. Based results EAE is understood....
We investigate the electron heating dynamics in electropositive argon and helium capacitively coupled RF discharges driven at 13.56 MHz by particle-in-cell simulations an analytical model. The model allows one to calculate electric field outside electrode sheaths, space time resolved within period. Electrons are found be heated strong ambipolar fields sheath during phase of expansion addition classical heating. By tracing individual electrons we also show that ionization is primarily caused...
Electron heating and ionization dynamics in capacitively coupled radio frequency (RF) atmospheric pressure microplasmas operated helium are investigated by particle-in-cell simulations semi-analytical modeling. A strong of electrons the plasma bulk due to high electric fields observed at distinct times within RF period. Based on model field is identified be a drift caused low electrical conductivity electron–neutral collision pressure. Thus, mainly ohmic this 'Ω-mode'. The phase strongest...
Low pressure capacitive radio frequency (RF) plasmas are often described by equivalent circuit models based on fluid approaches that predict the self-excitation of resonances, e.g., high oscillations total current in asymmetric discharges, but do not provide a kinetic interpretation these effects. In fact, they leave important questions open: How is continuity ensured presence energetic electron beams generated expanding sheaths lead to local enhancement conduction propagating through bulk?...
Self-organized spatial structures in the light emission from ion-ion capacitive RF plasma of a strongly electronegative gas (CF4) are observed experimentally for first time. Their formation is analyzed and understood based on particle-based kinetic simulations. These "striations" found to be generated by resonance between driving radio-frequency eigenfrequency (derived an analytical model) that establishes modulation electric field, ion densities, as well energy gain loss processes electrons...