ADVANCES IN LANGMUIR PROBE DIAGNOSTICS OF THE PLASMA POTENTIAL AND ELECTRON-ENERGY DISTRIBUTION FUNCTION IN FUSION PLASMAS (IWSSPP 2016)

0461433 - ÚFP 2017 BG eng A - Abstract
Popov, Tsv.K. - Dimitrova, Miglena - Ivanova, P. - Kovacic, J. - Gyergyek, T. - Dejarnac, Renaud - Stöckel, Jan - Pedrosa, M.A. - Lopez-Bruna, D. - Hidalgo, C. - Pánek, Radomír
ADVANCES IN LANGMUIR PROBE DIAGNOSTICS OF THE PLASMA POTENTIAL AND ELECTRON-ENERGY DISTRIBUTION FUNCTION IN FUSION PLASMAS (IWSSPP 2016).
Proceedings of the 7th International Workshop and Summer School on Plasma Physics (IWSSPP 2016). Sofia: University of Sofia, 2016. s. 15. ISBN N
Institutional support: RVO:61389021
Keywords : Advanced Langmuir probe techniques * triple probe * first-derivative probe technique * plasma potential * electron energy distribution function * electron temperatura and density
Subject RIV: BL - Plasma and Gas Discharge Physics

Advanced Langmuir probe techniques are reviewed for evaluating the plasma potential and electron-energy distribution function (EEDF) in magnetized plasma. The classical, the triple probe and the first-derivative probe technique (FDPT) are discussed. The FDPT was applied to derive data for plasma parameters from the IV probe characteristics measured in the plasma boundary region in the COMPASS and ISTTOK tokamaks, as well as in the TJ-II stellarator. In the COMPASS tokamak in the vicinity of the last closed flux surface (LCFS) the EEDF is bi-Maxwellian with the low-temperature electron fraction predominating over the higher temperature one, whereas in the far scrape off layer (SOL) the EEDF is Maxwellian. The comparison of the results from probe measurements with the ASTRA package and EIRENE code calculations suggests that the main reason of the appearance of a bi-Maxwellian EEDF in the vicinity of the LCFS is the ionization of the neutral atoms. In the SOL the radial distribution of the parallel power flux density is a double exponential. In the calculations of the parallel power flux density the energy losses from inelastic processes must be taken into account.
Permanent Link: http://hdl.handle.net/11104/0261029