An advanced Thomson scattering system has been built for a linear plasma generator for plasma surface interaction studies. The Thomson scattering system is based on a Nd:YAG laser operating at the second harmonic and a detection branch featuring a high etendue (f /3) transmission grating spectrometer equipped with an intensified charged coupled device camera. The system is able to measure electron density (n e ) and temperature (T e ) profiles close to the output of the plasma source and, at a distance of 1.25 m, just in front of a target. The detection system enables to measure 50 spatial channels of about 2 mm each, along a laser chord of 95 mm. By summing a total of 30 laser pulses (0.6 J, 10 Hz), an observational error of 3% in n e and 6% in T e (at n e = 9.4 × 10 18 m −3 ) can be obtained. Single pulse Thomson scattering measurements can be performed with the same accuracy for n e > 2.8 × 10 20 m −3 . The minimum measurable density and temperature are n e < 1 × 10 17 m −3and T e < 0.07 eV, respectively. In addition, using the Rayleigh peak, superimposed on the Thomson scattered spectrum, the neutral density (n 0 ) of the plasma can be measured with an accuracy of 25% (at n 0 = 1 × 10 20 m −3 ). In this report, the performance of the Thomson scattering system will be shown along with unprecedented accurate Thomson-Rayleigh scattering measurements on a low-temperature argon plasma expansion into a low-pressure background.

Decay of the electron density and the electron collision frequency between successive discharges of a pulsed plasma jet in N 2 . Plasma Sources Science and Technology, 28(3), [035020].

A 1D plug flow model suitable for describing the CO2 conversion into CO in microwave plasma reactors is proposed. The model is applied together with the Antwerp data set for the CO2 reaction kinetics to calculate parameter scans for a realistic experimental set up. The energy re-distribution pathways in the model calculations are analyzed. The analysis shows that despite the input power being initially deposited mainly into vibrational states the fast vibrational-translational (VT) transfer leads to dissociation of CO2 predominantly via the thermal quenching mechanism. Solutions with mitigated VT-losses can be obtained by increasing the specific input power–power per unit volume. In this regime the energy efficiency starts to be constrained by reverse processes.

Pathway analysis is used as a selection method to determine which reaction rate coefficient uncertainties need to be included for the uncertainty analysis, as a fast alternative for sensitivity analysis. This requires the pathway analysis implementation to include the analysis of the electron power density. Results from pathway analysis as a selection method are compared with results from sensitivity analysis. For a nitrogen chemistry we show the agreement in results between pathway analysis and sensitivity analysis, and additionally results of the uncertainty analysis. We also apply the method to a CO 2 chemical system that involves vibrationally excited states to demonstrate the excellent performance of this method for complex systems.

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