Fig. 5From: Non-invasive assessment of plasma parameters inside an ion thruster combining optical emission spectroscopy and principal component analysisThe two strongest lines (see Fig. 4) of intensity-normalized xenon spectra for a measurement series at 0.1 sccm gas flow at different operating points (see also Fig. 6) (a) together with the corresponding Langmuir double probe measurements (b). This series of spectra is part of the reference data setBack to article page