A5057651681- Plasma Diagnostics and Applications
- Plasma Applications and Diagnostics
- Atomic and Molecular Physics
- Semiconductor materials and devices
- High voltage insulation and dielectric phenomena
- Catalytic Processes in Materials Science
- Diamond and Carbon-based Materials Research
- Electrohydrodynamics and Fluid Dynamics
- Mass Spectrometry Techniques and Applications
- CO2 Reduction Techniques and Catalysts
- Ammonia Synthesis and Nitrogen Reduction
- Advanced Chemical Physics Studies
- Laser-induced spectroscopy and plasma
- Electrocatalysts for Energy Conversion
- Gas Dynamics and Kinetic Theory
- Dust and Plasma Wave Phenomena
- Particle accelerators and beam dynamics
- Gas Sensing Nanomaterials and Sensors
- Metal and Thin Film Mechanics
University of Michigan
2025
Instituto Superior Técnico
2023-2024
University of Lisbon
2019-2023
Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento
2023
Abstract This work presents a reaction mechanism for oxygen plasmas, i.e. set of reactions and corresponding rate coefficients that are validated against benchmark experiments. The kinetic scheme is in DC glow discharge gas pressures 0.2–10 Torr currents 10–40 mA, using the 0D LisbOn KInetics simulation tool available experimental data. comparison comprises not only densities main species discharge— <?CDATA $\mathrm{O_2}(\mathrm{X}^3\Delta_\mathrm{g}^-)$?> <mml:math...
Abstract Plasmas interacting with liquid surfaces produce a complex interfacial layer where the local chemistry in is driven by fluxes from gas phase of electrons, ions, photons, and neutral radicals. Typically, surface has at best mild curvature impinging plasma species applied electric field being nominally normal to surface. With liquids such as water having high dielectric constant, structuring producing wavy enables enhancement due polarization liquid, well regions higher lower...
Abstract This work proposes an updated set of electron-impact cross sections for carbon dioxide (CO2) by quantitatively identifying CO2 dissociation within the two electronic excitation channels proposed Phelps. In particular, section with energy threshold at 7 eV is considered a 15% branching ratio and associated into O(1D)+CO(X), while one 10.5 used entirely O(3P)+CO(a3Πr). Experimental data on rate coefficients moderate reduced electric field (E/N), conversion efficiencies high E/N,...
Abstract A comprehensive solution of the electron kinetics in gas discharges, accounting for dependencies space, velocity and time, is often unfeasible. Therefore, behavior frequently coupled to fluid models under one two assumptions: local-field approximation (LFA), which equates steady-state calculation with local instantaneous value reduced electric field; or local-energy (LEA), rate coefficients power distribution among different collisional channels depend on mean energy. In this work,...
Oxygen atom densities were measured in situ a CO 2 glow discharge, at pressures between 0.2 and 5 Torr .Two measurement techniques compared, namely optical emission actinometry (using Ar as the actinometer) High-Resolution Two-photon Absorption Laser Induced Fluorescence (HR-TALIF) normalised to Xe, found give consistent results.The variation of atomic oxygen density with gas pressure shows two different regimes transition around 1 Torr.Measurements O loss frequency under plasma exposure...
Energetic species produced by gas-phase plasmas that impinge on a liquid surface can initiate physicochemical processes at the gas/liquid interface and in phase. The interaction of these energetic with phase chemical reaction pathways referred to as plasma-driven solution electrochemistry (PDSE). There are several processing opportunities challenges presented PDSE. These include potential use PDSE activate difficult other approaches well renewable electricity generate could make liquid-phase...
This work explores the effect of O2 addition on CO2 dissociation and vibrational kinetics CO under various non-equilibrium plasma conditions. A self-consistent model, previously validated for pure discharges, is further extended by adding CO, including electron impact excitation de-excitation (e-V), vibration-to-translation relaxation (V-T) vibration-to-vibration energy exchange (V-V) processes. The considered include levels up to v = 10 v1=2 v2=v3=5, respectively symmetric stretch, bending...
The LisbOn KInetics Monte Carlo (LoKI-MC) is an open-source simulation tool that solves the electron kinetics for low-temperature plasmas excited by uniform DC electric fields from different gas mixtures, using techniques. Following strategy and data organization of Boltzmann (LoKI-B) solver, program easily addresses any complex mixture atomic/molecular species, describing collisions with target state (electronic, vibrational rotational), characterized user-prescribed population. LoKI-MC...
This work explores the effect of N2 addition on CO2 dissociation and vibrational kinetics CO under various non-equilibrium plasma conditions. A self-consistent kinetic model, previously validated for pure CO2-O2 discharges, is further extended by adding N2. The considered include levels up to v = 10 CO, 59 v1 2 v2 v3 5, respectively symmetric stretch, bending asymmetric stretch modes CO2, account electron-impact excitation de-excitation (e-V), vibration-to-translation (V-T)...
Abstract The emission spectra of a streamer discharge in pure nitrogen provide an important tool for investigating the fundamental kinetics excited electronic states N 2 and benchmark data validating advanced kinetic schemes numerical models. In this work, we characterize monofilament developed dielectric barrier configuration, including electrical characteristics, time-resolved images /N <?CDATA $_2^+$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">...
Abstract Surface recombination in an oxygen DC glow discharge a Pyrex (borosilicate glass) tube is studied via mesoscopic modelling and comparison with measurements of probability. A total 106 experimental conditions are assessed, current varying between 10 40 mA, pressure values ranging 0.75 Torr, fixed outer wall temperatures ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>T</mml:mi> <mml:mi mathvariant="normal">w</mml:mi>...
This work focuses on the benchmarking between a zero-dimensional (0D) global model (LoKI) and one-dimensional (1D) radial fluid for positive column of oxygen DC glow discharges in tube 1 cm inner radius at pressures 0.5 Torr 10 Torr. The data used two models are same, so that difference is reduced to dimensionality. A good agreement found main discharge parameters, with relative differences below 5%. species average number densities, charged neutral, slightly worse, increasing pressure from...
Abstract This work proposes a complete and consistent set of cross sections (CSs) for electron collisions with water molecules to be published in the IST-Lisbon database on LXCat. The is validated from comparison between experimental computed swarm parameters. former are collected literature while latter calculated using space-homogeneous two-term Boltzmann solver, assuming isotropic scattering inelastic collisions. Rotational CSs, based Born approximation, optimised by means analysis...
Abstract This work proposes a complete and consistent set of cross sections (CS) for electron collisions with water gas molecules to be published in the IST-Lisbon database on LXCat. The is validated by swarm analysis technique. anisotropic angular distribution electrons rotational considered means Born approximation two-term Boltzmann solver (LisbOn KInetics (LoKI-B)) Monte Carlo simulations code (LoKI-MC), both freely available as open-source codes. inclusion scattering significantly...
Abstract This work presents a numerical study of the electron kinetics under AC/DC electric fields and DC magnetic crossed at arbitrary angles. The physical phenomena are studied both in model gases (Reid-ramp Lucas–Saelee) real (N 2 Ar). simulations carried out with an upgraded version Monte Carlo open-source code LoKI-MC. is compared against several independent benchmark calculations available literature. In addition, new for solvers produced conditions coexistent AC fields, accounting...
Abstract This work presents a kinetic Monte Carlo algorithm to solve the gas-phase chemistry in low-temperature plasmas, as first effort achieve unified formulation of electron and heavy-particle kinetics based on techniques. The implemented is successfully validated thermodynamic limit from comparison with traditional deterministic description using rate-balance equations. accuracy rare species strongly depends number particles used simulation. To surpass this limitation, two novel variance...
Abstract Vibrational distributions of electronically excited states N 2 obtained through dipole-allowed radiative transitions provide an important tool to study the kinetics non-equilibrium plasmas under various discharge conditions. In this work, we report, for first time, streamer-induced visible/near-infra-red emission spectra developing during hundred nanoseconds after initiation discharge. Emission positive system was acquired in 500–1100 nm range, which allows a complete analysis (B...
This work focuses on the benchmarking between a zero-dimensional (0D) global model (LoKI) and one-dimensional (1D) radial fluid for positive column of oxygen DC glow discharges in tube 1 cm inner radius at pressures 0.5 Torr 10 Torr. The data used two models are same, so that difference is reduced to dimensionality. A good agreement found main discharge parameters, with relative differences below 5%. species average number densities, charged neutral, slightly worse, increasing pressure from...
This work presents a reaction mechanism for oxygen plasmas, i.e. set of reactions and corresponding rate coefficients that are validated against benchmark experiments. The kinetic scheme is in DC glow discharge gas pressures 0.2-10 Torr currents 10-40 mA, using the 0D LisbOn KInetics (LoKI) simulation tool available experimental data. comparison comprises not only densities main species - $\mathrm{O_2(X^3\Sigma_g^-)}$, $\mathrm{O_2(a^1\Delta_g)}$, $\mathrm{O_2(b^1\Sigma_g^+)}$...