Modelling of a miniature microwave driven nitrogen plasma jet and comparison to measurements

The MMWICP (miniature microwave ICP) is a new plasma source using the induction principle. Recently Klute et al presented a mathematical model for the electromagnetic fields and power balance of the new device. In this work the electromagnetic model is coupled with a global chemistry model for nitrogen, based on the chemical reaction set of Thorsteinsson and Gudmundsson and customized for the geometry of the MMWICP. The combined model delivers a quantitative description for a non-thermal plasma at a pressure of p = 1000 Pa and a gas temperature of Tg = 650–1600 K. Comparison with published experimental data shows a good agreement for the volume averaged plasma parameters at high power, for the spatial distribution of the discharge and for the microwave measurements. Furthermore, the balance of capacitive and inductive coupling in the absorbed power is analyzed. This leads to the interpretation of the discharge regime at an electron density of ne ≈ 6.4 × 1018 m−3 as E/H-hybridmode with an capacitive and inductive component

Modelling of a miniature microwave driven nitrogen plasma jet and comparison to measurements

The MMWICP (miniature microwave ICP) is a new plasma source using the induction principle. Recently Klute et al presented a mathematical model for the electromagnetic fields and power balance of the new device. In this work the electromagnetic model is coupled with a global chemistry model for nitrogen, based on the chemical reaction set of Thorsteinsson and Gudmundsson and customized for the geometry of the MMWICP. The combined model delivers a quantitative description for a non-thermal plasma at a pressure of p = 1000 Pa and a gas temperature of Tg = 650–1600 K. Comparison with published experimental data shows a good agreement for the volume averaged plasma parameters at high power, for the spatial distribution of the discharge and for the microwave measurements. Furthermore, the balance of capacitive and inductive coupling in the absorbed power is analyzed. This leads to the interpretation of the discharge regime at an electron density of ne ≈ 6.4 × 1018 m−3 as E/H-hybridmode with an capacitive and inductive component

3-dimensional semi-analytic model of a microwave driven miniature plasma jet

Microwave or Radio frequency driven plasma jets play an important role in various technical applications and are usually operated in a capacitive mode. The MiniatureMicroWaveICP (MMWICP) is a new promising plasma source and successfully transfers the induction principle to a miniature plasma jet. This work presents a 3-dimensional semi-analytic model of the electron density of the MMWICP. The model is based on a drift-diffusion equation which is coupled to the electromagnetic model of the MMWICP presented by Klute et al in Plasma Sources Sci. Technol. 29 065018 (2020). An analytic solution is found by expanding the expression of the electron density into a series of eigenfunctions. The 3-dimensional profile of the electron density is simulated for characteristic values of the power absorbed by the plasma. The results show that the spatial distribution of the electron density is highly depended on the absorbed power. The results are found to be in good agreement with experimental measurements.74th Annual Gaseous Electronics Conferenc

Numerical investigation of a DC glow discharge in an Argon gas : two-component plasma model

Abstract only

Doğru akım ışıltılı deşarj özelliklerinin numerik araştırılması:

This thesis deals with a one and two dimensional numerical modeling of a low-pressure DC glow discharge in argon gas. We develop two-component fluid model which uses the diffusion-drift theory for the gas discharge plasma and consists of continuity equations for electrons and ions, as well as Poisson equation for electric field. Numerical method is based on the control volume technique. Calculations are carried out in MATLAB environment. Computed results are compared with the classic theory of glow discharges and available experimental data.M.S. - Master of Scienc

Error assesment for QSS of CRM via chemical reduction technique : Ar and Hg plasmas

Conventional Collisional Radiative Models (CRMs) lessen the computational load of simulating reactive flows by assuming that most of the plasma species are in Quasi Steady State (QSS) [1]. For such species the solution of transport equations can be avoided. However, the traditional formalism lacks a good measure of the error that is made by this approximation. In order to fill this gap, a relation is established between the CRM method and the Chemical Reduction Technique (CRT) [2,3]. Both methods have the same goal: to reduce the number of transport equations without eliminating reaction channels. The reduction technique is based on the diagonalisation of the source jacobian. It allows a more precise assessment of the errors induced by the QSS assumption. By diagonalisation, the problem is rewritten in terms of linear combinations of the pecies densities, whose evolution in time is characterised by decay times that are related to the corresponding eigenvalues. In this contribution, the application to both atomic Ar and Hg plasmas is discussed. The results show agreement with the CRM literature [1]. For common plasma parameters, only the atom and ion ground state densities need to be dealt with explicitly, while the other (excited) states can be assumed to be quasi-steady. A detailed analysis of the error will be provided. [1] Dijk J van, Hartgers A, Jonkers J, Mullen J J A M van der (2001) Collisional radiative models with multiple transport-sensitive levels- application to high electron density mercury discharges.Journal of Physics D: Applied Physics, 34(10), 1499-1509 [2] Eggels R L M G (1996) Modelling of Combustion Processes and NO Formation with Reduced Reaction Mechanisms PhD Thesis Eindhoven University of Technology [3] Pope S B, Maas U (1992) Simplifying chemical kinetics: Intrinsic low dimensional manifolds in composition space. Combustion and Flame, 88:239-26

Simplifying plasma chemistry via ILDM

\u3cp\u3eA plasma fluid model containing a large number of chemical species and reactions yields a high computational load. One of the methods to overcome this difficulty is to apply Chemical Reduction Techniques as used in combustion engineering. The chemical reduction technique that we study here is ILDM (Intrinsic Lower Dimensional Manifold). The ILDM method is used to simplify an argon plasma model and then a comparison is made with a CRM (Collisional Radiative Model).\u3c/p\u3

Global (volume-averaged) model of inductively coupled chlorine plasma: Influence of Cl wall recombination and external heating on continuous and pulse-modulated plasmas

International audienceAn inductively coupled radio-frequency plasma in chlorine is investigated via a global (volume-averaged) model, both in continuous and square wave modulated power input modes. After the power is switched off (in a pulsed mode) an ion?ion plasma appears. In order to model this phenomenon, a novel quasi-neutrality implementation is proposed. Several distinct Cl wall recombination probability measurements exist in the literature, and their effect on the simulation data is compared. We also investigated the effect of the gas temperature that was imposed over the range 300?1500 K, not calculated self-consistently. Comparison with published experimental data from several sources for both continuous and pulsed modes shows good agreement with the simulation results

A computational analysis of the vibrational levels of molecular oxygen in low-pressure stationary and transient radio-frequency oxygen plasma

International audienceVibrational levels of molecular oxygen, O 2 ( v &#8201;&#8201;<&#8201;&#8201;42), are investigated in continuous and pulse-modulated low-pressure radio-frequency oxygen plasma with a global modelling approach. The model is benchmarked against a variety of pressure-, power- and time-resolved measurements of several inductive and asymmetric capacitive discharges available in the literature, and a good agreement is obtained. The sensitivity of the model with respect to the vibrational kinetics, the wall reactions and the spatial inhomogeneity of the charged particles are presented. The simulations without the vibrational levels are also shown for the sake of comparison