Single Langmuir probe characteristic in a magnetized plasma at the text tokamak
- Univ. of Texas, Austin, TX (United States)
A single Langmuir probe tip was used at TEXT-Upgrade to obtain I-V characteristics in a magnetized plasma. Noisy data were reduced by a boxcar-averaging routine. Unexpected effects, namely nonsaturation of ion current, hysterises in the characteristics and I(V)-data were observed, which are in disagreement to the common single probe model. A double probe model allows parameterization of the I(V) curves and to determine the plasma properties in the scrape-off layer. It is shown in this model that a Langmuir probe does perturb the local space potential in the plasma. Comparisons were made with the triple probe technique of measuring temperatures. The nonsaturation of ion current leads to an error in the triple probe technique of order 20%.
- Research Organization:
- Texas Univ., Austin, TX (United States). Fusion Research Center
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG03-94ER54241
- OSTI ID:
- 69162
- Report Number(s):
- DOE/ER/54241--138; FRCR--456; ON: DE95012144
- Country of Publication:
- United States
- Language:
- English
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