Comparison of Langmuir probe and laser Thomson scattering methods in the electron temperature measurement in divertor simulator MAP-II

摘要

In order to investigate details of anomaly in the Langmuir probe current (I)-voltage (V) characteristics, electron temperatures and densities are measured by both Langmuir probe and laser Thomson scattering methods. The electron densities measured with both methods show good agreement in hydrogen-molecular assisted recombination (H-2-MAR) plasmas. On the other hand, the electron temperatures measured with Langmuir probe are overestimated compared with that obtained from the Thomson scattering spectrum in the H2-MAR plasmas. Histogram of electron current deviated from its average shows that fluctuation appeared in the electron current becomes large and the histogram distorted in temperature-overestimated condition, especially when the probe voltage is negatively biased. (C) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.