Tiago Silva

Tiago Silva
Technical University of Lisbon | UTL · Institute for Plasma Research and Nuclear Fusion (IPFN)

Ph D

About

37
Publications
9,935
Reads
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878
Citations
Citations since 2016
27 Research Items
836 Citations
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
Additional affiliations
November 2011 - November 2015
Université de Mons
Position
  • PhD Student

Publications

Publications (37)
Article
The time evolution of the CO2 dissociation fraction in pulsed discharges is studied through kinetic modeling. The simulations are compared against experimental data obtained in pulsed DC glow and radio-frequency discharges, operated with currents of about 40 mA and powers of 40 W, sustained under low gas pressures (< 600 Pa). The model is used to a...
Article
Full-text available
Numerous applications have required the study of CO2 plasmas since the 1960s, from CO2 lasers to spacecraft heat shields. However, in recent years, intense research activities on the subject have restarted because of environmental problems associated with CO2 emissions. The present review provides a synthesis of the current state of knowledge on th...
Article
The number of numerical models and their complexity are increasing rapidly. This goes together with a bigger impact in various fields, but also with a growing opacity. In the case of a deterministic model with hundreds of inputs, it can become difficult, while crucial, to identify which mechanisms are the most influential on the results. Screening...
Article
A consistent theoretical analysis of a pulsed DC glow discharge operating at pressure of 5 Torr, current of 50 mA and plasma pulse of 5 ms in CO2 is presented. The model couples the electron Boltzmann equation to a rate balance equations involving ∼70 individual vibrational states. The kinetic scheme and the corresponding e-V, V-T and V-V rate coef...
Article
Full-text available
This is the second of two papers presenting the study of vibrational energy exchanges in non-equilibrium CO2 plasmas in low-excitation conditions. The companion paper addresses a theoretical and experimental investigation of the time relaxation of ∼70 individual vibrational levels of ground-state CO molecules during the afterglow of a pulsed DC glo...
Article
Full-text available
Sending a manned mission to Mars is one of the next major steps in space exploration. Creating a breathable environment, however, is a substantial challenge. A sustainable oxygen supply on the red planet can be achieved by converting carbon dioxide directly from the Martian atmosphere. A new solution to do so is on the way: Plasma technology.
Article
Significant improvement in the energy efficiency of plasma-assisted CO2 conversion is achieved with applied power modulation in a surfaguide microwave discharge. The obtained values of CO2 conversion and energy efficiency are, respectively, 0.23 and 0.33 for a 0.95 CO2 + 0.05 N2 gas mixture. Analysis of the energy relaxation mechanisms shows that p...
Article
A kinetic model describing the time evolution of ∼70 individual CO2(X1Σ⁺) vibrational levels during the afterglow of a pulsed DC glow discharge is developed in order to contribute to the understanding of vibrational energy transfer in CO2 plasmas. The results of the simulations are compared against in situ Fourier transform infrared spectroscopy da...
Article
Herein, it is argued that Mars has nearly ideal conditions for CO2 decomposition by non-equilibrium plasmas. It is shown that the pressure and temperature ranges in the CO2 Martian atmosphere favour the vibrational excitation and subsequent up-pumping of the asymmetric stretching mode, which is believed to be a key factor for an efficient plasma di...
Article
Reactive high-power impulse magnetron sputteringdischarge has been studied experimentally combining optical emission, absorption, and laser-based diagnostic techniques. The quantification of the atomic ground state densities is performed using optical emission spectroscopy. Hysteresis behavior as a function of molecular oxygen flow fraction in Ar-O...
Article
http://onlinelibrary.wiley.com/doi/10.1002/ppap.201600185/full An Ar plasma sustained by a surfaguide wave launcher is investigated at intermediate pressure (200–2667 Pa). Two 2D self-consistent models (quasi-neutral and plasma bulk-sheath) are developed and benchmarked. The complete set of electromagnetic and fluid equations and the boundary condi...
Data
Full-text available
Supporting information to Understanding Microwave Surface-Wave Sustained Plasmas at Intermediate Pressure by 2D Modeling and Experiments. Plasma Process Polym (2017) 14, 1600185. doi:10.1002/ppap.201600185
Article
Full-text available
Back Cover: Cross-sectional view of a microwave plasma column at a pressure of 933 Pa. The Ar, N2 or CO2 plasma is sustained by a surfaguide launcher. Modeling shows that the power is deposited along the plasma-dielectric boundary (the tube wall), where the surface wave propagates. This paper presents and benchmarks two 2-dimensional models (quasi-...
Article
The ground state density of oxygen atoms in reactive high-power impulse magnetron sputtering discharges has been studied quantitatively. Both time-resolved and space-resolved measurements were conducted. The measurements were performed using two-photon absorption laser-induced fluorescence (TALIF), and calibrated by optical emission actinometry wit...
Article
The growing interest to plasma-based greenhouse gas decomposition requires the knowledge of the different kinetic mechanisms inherent in CO2 discharges and post-discharges. This automatically involves extensive plasma diagnostics research work. Among different types of plasma diagnostics, the ones based on optical spectroscopy are of particular rel...
Article
Full-text available
The CO2 conversion into value-added products has gained significant interest over the last years as the greenhouse gas concentrations constantly increase due to anthropogenic activities. We report here on experiments for CO2 conversion by means of cold atmospheric plasma using a cylindrical flowing dielectric barrier discharge (DBD) reactor. A deta...
Article
A surfaguide microwavedischarge operating at 2.45 GHz in Ar and Ar-CO2 mixtures is studied using diagnostics methods based on optical emission spectroscopy. The population densities of Ar metastable and resonant states of the lowest group of excited levels (1sx) are investigated for several experimental conditions using the self-absorption techniqu...
Article
Full-text available
In this experimental work, a flowing dielectric barrier discharge operating at atmospheric pressure is used for the splitting of CO2 into O2 and CO. The influence of the applied frequency and plasma power on the microdischarge properties is investigated to understand their role on the CO2 conversion. Electrical measurements are carried out to expla...
Article
Full-text available
A chemical kinetics model is developed for a CO 2 /N 2 microwave plasma, focusing especially on the vibrational levels of both CO 2 and N 2. The model is used to calculate the CO 2 and N 2 conversion as well as the energy efficiency of CO 2 conversion for different power densities and for N 2 fractions in the CO 2 /N 2 gas mixture ranging from 0 to...
Article
In this research, conversion of carbon dioxide and water vapor into value-added chemicals has been investigated in a pulsed surfacewave sustained microwave discharge operating under different conditions. Formation of syngas (CO/H2) was observed. The influence of the gas mixture ratio, the specific energy input (SEI), Espec, and the feed flow rate o...
Article
Full-text available
In this work, a new plasma diagnostic method has been used to quantify the plasma-generated species that play a part in the ethyl lactate plasma polymer film deposition. This method has been possible by using the RGA mass spectrometry combined with the in situ FTIR spectroscopy supported by DFT calculations. Ethyl lactate plasma phase can then be q...
Article
A simple gas temperature determination method based on the line ratio between two rotational peaks from the CO Angstrom rotational emission band is reported. A formula based on CO spectral synthesis provides a way for temperature control in plasmas containing CO molecules. This approach is validated in a CO2 flowing gas surfaguide microwave dischar...
Article
Conversion of CO2 into CO and O is studied in a flowing gas surfaguide pulsed microwave discharge operating with CO2 and CO2 + N2 gas mixtures under different conditions. Optical emission spectroscopy, including actinometry (using N2), vibrational (N2 molecule) and rotational (CO and N2 molecules) analysis are utilized. Both time- and space-resolve...
Article
Time-resolved mass spectrometry (MS) study of a high-power impulse magnetron sputtering discharge (HiPIMS) operating in the 'short-pulse' regime (5 µs) at 1 kHz of the repetition frequency is undertaken. Several time-resolved effects related to both Ti+ and Ar+ ion energy distribution functions (IEDF) are found. In particular, the dynamics of both...
Article
A hydrodynamic model was developed to simulate the flow and the heat transfer with the gas/plasma system produced by a microwave-driven (500-900 W at 2.45 GHz) axial injection torch, running in atmospheric pressure helium at 3-9 L min-1 input gas flows. The model solves the Navier-Stokes' equations, including the effect of the plasma upon the momen...

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Project (1)
Project
Our goal is to establish the relationship between the plasma physics and chemistry and the properties of the deposited thin films during reactive magnetron sputtering or high-power impulse magnetron sputtering discharges.