Influence of temperature fluctuations on plasma turbulence investigations with Langmuir probes

被引：60

作者：

Nold, B. ^{[1
]}

Ribeiro, T. T. ^{[2
]}

Ramisch, M. ^{[1
]}

Huang, Z. ^{[1
]}

Mueller, H. W. ^{[2
]}

Scott, B. D. ^{[2
]}

Stroth, U. ^{[1
,2
]}

机构：

[1] Univ Stuttgart, Inst Plasmaforsch, D-70569 Stuttgart, Germany

[2] EURATOM, Max Planck Inst Plasmaphys, Garching, Germany

来源：

NEW JOURNAL OF PHYSICS | 2012年 / 14卷

关键词：

FLUX TUBE TREATMENTS; ELECTRON-TEMPERATURE; EDGE TURBULENCE; EMISSIVE PROBE; SPACE-CHARGE; TRANSPORT; BOUNDARY; MODELS; DIAGNOSTICS; SCATTERING;

D O I：

10.1088/1367-2630/14/6/063022

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The reliability of Langmuir probe measurements for plasma-turbulence investigations is studied on GEMR gyro-fluid simulations and compared with the results from conditionally sampled I-V characteristics as well as electron-emitting probe measurements close to the last closed flux surface of the tokamak ASDEX Upgrade. In this region, simulation and experiment consistently show coherent in-phase fluctuations in density, plasma potential and also electron temperature. Ion-saturation current measurements turn out to reproduce density fluctuations quite well. Fluctuations in the floating potential, however, are strongly influenced by temperature fluctuations and, hence, are strongly distorted compared to the actual plasma potential. These results suggest that interpreting floating as plasma-potential fluctuations while disregarding temperature effects is not justified near the separatrix of hot fusion plasmas. Here, floating potential measurements led to corrupted results on the E x B dynamics of turbulent structures in the context of, e.g., turbulent particle and momentum transport or turbulence characterization on the basis of density-potential phase relations.

引用

页数：13

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