Three dimensional electromagnetic modelling of a free-standing CO2 microwave plasma has been performed, by describing the plasma as a dielectric medium. The relative permittivity and conductivity of the medium are parametrised. The waveguide geometry from experiment, including the tuner, is put into the model, knowing that this corresponds to maximum power transfer of the microwave generator to the plasma under plasma impedance matching conditions. Two CO2 plasma discharge regimes, differing mainly in pressure, input power and temperature, have been studied. The model's validity has been checked through study of materials of known conductivity. From measurements of the neutral gas temperature and the plasma electron density profile, the reduced electric field is determined. From the parametrisation of the dielectric properties, a range for the effective electron-neutral collision frequency for momentum transfer is estimated. The results for the reduced electric field and the range of the electron neutral collision frequency obtained, are consistent as verified by simulations using BOLSIG+. In addition, from this comparison it is possible to narrow down the range of the collision frequencies, and to estimate the electron temperature. The reduced electric field lies between 80 and 180 Td for the relatively low pressure, low input power, the so-called 'diffuse' regime. For the relatively high pressure, high input power ('contracted') regime it lies between 10 and 60 Td. The normalised collision frequency lies between 1.6 and 2.3 for the diffuse regime, while for the contracted regime it lies between 2 and 3. The electron temperature ranges from 2 to 3 eV for the diffuse regime, and from 0.5 to 1 eV for the contracted regime. Related content: 10.1088/1361-6595/ab1ca1

VL - 28 IS - 7 U1 -MaSF

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U5 - 563dcc592c1a5834f7f65e6168d00c5e ER - TY - JOUR T1 - Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry JF - Journal of Visualized Experiments Y1 - 2017 A1 - van den Bekerom, D. C. M. A1 - den Harder, N. A1 - Minea, T. A1 - Gatti, N. A1 - Palomares-Linares, J. M. A1 - Bongers, W. A. A1 - M. C. M. van de Sanden A1 - G. J. van Rooij AB - This article describes a flowing microwave reactor that is used to drive efficient non-equilibrium chemistry for the application of conversion/activation of stable molecules such as CO2, N2 and CH4. The goal of the procedure described here is to measure the in situ gas temperature and gas conversion. VL - 2017 UR - https://www.jove.com/video/55066/non-equilibrium-microwave-plasma-for-efficient-high-temperature IS - 126 U1 - MaSF U2 - NFC U3 - FP00 U5 - 99c4e26e071750e0fe65ee1010f747ef ER - TY - JOUR T1 - New millimeter-wave access for JET reflectometry and ECE JF - Fusion Engineering and Design Y1 - 2005 A1 - Cupido, L. A1 - de la Luna, E. A1 - Antonucci, C. A1 - Guigon, A. A1 - van Amerongen, F. A1 - Bongers, W. A. A1 - Donne, A. J. H. A1 - M. F. Graswinckel A1 - Bruschi, A. A1 - Cirant, S. A1 - Simonetto, A. A1 - Sozzi, C. A1 - Wagner, D. A1 - Manso, E. A1 - Meneses, L. A1 - Silva, F. A1 - Varela, P. A1 - Balshaw, N. A1 - Chareau, J. M. A1 - Conway, G. A1 - Fessey, J. A1 - Hanks, S. A1 - Pearce, R. A1 - Ricardo, V. A1 - Sands, D. A1 - Starky, D. A1 - Tisconia, T. VL - 74 SN - 0920-3796 UR -