32 research outputs found
Analysis of the temperature influence on Langmuir probe measurements on the basis of gyrofluid simulations
The influence of the temperature and its fluctuations on the ion saturation
current and the floating potential, which are typical quantities measured by
Langmuir probes in the turbulent edge region of fusion plasmas, is analysed by
global nonlinear gyrofluid simulations for two exemplary parameter regimes. The
numerical simulation facilitates a direct access to densities, temperatures and
the plasma potential at different radial positions around the separatrix. This
allows a comparison between raw data and the calculated ion saturation current
and floating potential within the simulation. Calculations of the
fluctuation-induced radial particle flux and its statistical properties reveal
significant differences to the actual values at all radial positions of the
simulation domain, if the floating potential and the temperature averaged
density inferred from the ion saturation current is used.Comment: Submitted to Plasma Physics and Controlled Fusio