Space potential, temperature, and density profile measurements on RENTOR
Radial profiles of the space potential, electron temperature, and density were measured on RENTOR with a heavy ion beam probe. The potential profile was compared to predictions from a stochastic magnetic field fluctuation theory, using the measured temperature and density profiles. The comparison shows strong qualitative agreement in that the potential is positive and order of T/sub e//e. There is some quantitative disagreement in that the measured radial electric fields are somewhat smaller than the theoretical predictions. To facilitate this comparison, a detailed analysis of the possible errors has been completed. The radial potential profile is broad and has a central peak value of approx. + 150 volts, with absolute errors of +/- 30 volts. The potential at the radial limit of measurements (r = 10 cm) is typically greater than + 100 volts. Thus, in the bulk of the RENTOR plasma, the radial electric field is less than 5 volts/cm. Between the r = 10 cm limit of measurements and the r = 15 cm chamber wall, the average radial electric field must be approx. 20 volts/cm. Fluctuations were observed in both the potential and abundance measurements made by the beam probe. These fluctuations are consistent with m = 1 to m = 4 MHD modes rotating at the electron diamagnetic drift velocity.
- Research Organization:
- Rensselaer Polytechnic Inst., Troy, NY (USA)
- OSTI ID:
- 5746636
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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