1 - Nuclear Sciences and Applications - IAEA

IAEA-CN-50/A-II-2 109
the soft X-rays. It is reasonable to believe, however, that the modes seen in
the plasma during this time are modified from those that would have been
observed in the absence of the plates. Some of the disruption characteristics,
such as the slow growth and locking of low frequency modes just prior to the
disruption, appear to be resistive in nature, and the separation between the
passive plates and the plasma edge must be reduced closer to the design value
of a few cm in order to suppress these "resistive" instabilities.
While the MHD activity at low P has not yet been fully explored and
controlled, these early results suggest positive benefits of the new geometry to
attain and study very high-(3 tokamak plasmas.
After optimization of plasma parameters with large current ramping and
strong shaping, the future addition of RF techniques shold allow the fine scale
control of the plasma pressure and current profiles to optimize access to the
second stability regime.
ACKNOWLEDGEMENT
The authors are pleased to acknowledge discussions with N. Suzuki.
REFERENCES
[1] GREENWALD, M., et ah, Phys. Rev. Lett. 53 (1984) 352.
[2] STRACHAN, J., Phys. Rev. Lett 58 (1987) 1004.
[3] BOL, K., et al., Phys. Rev. Lett. 57 (1986) 1891.
[4] REWOLDT, G., TANG, W.M., HASTIE, R.J., Phys. Fluids 30 (1987) 807.
[5] REWOLDT, G., Princeton Univ., personal communications, 1988.