Modelling of expected B, C, N and O Lyman-α line intensities emitted from W7-X plasmas and measured by means of the W7-X light impurity monitor system

Abstract The “C/O Monitor” for Wendelstein 7-X (W7-X) is a dedicated light impurity XUV spectrometer intended to measure Lyman-α transitions of hydrogen-like ions four low-Z impurities—boron (4.9 nm), carbon (3.4 nitrogen (2.5 nm) and oxygen (1.9 nm). Since the discussed diagnostic will deliver continuous information about line intensities, it crucial understand origin obtained signals with respect experimental plasma conditions (electron temperature density). This, however, might be difficult because broad acceptance angle irregular shape edge or SOL where radiation expected mostly come from, depending on temperature. For that reason, numerous analyses assuming various ranges electron density profiles W7-X plasmas have been performed (assuming corona equilibrium neglecting transport processes). aim this work estimate radiant flux determine sensitivity system impurity-level changes. It allow improve understanding between measured signal concentration.