Abstract
Recently at JET a pure helium campaign has been performed. The exploration of the density limit in L-mode limiter as well as L-mode and H-mode diverted plasmas was one of the main objectives. In L-mode plasmas the density can be increased until the total radiated power equals the heating power, hence the density limit is determined by a radiative collapse. When compared to deuterium plasmas the L-mode density limit in helium is twice as high. In H-mode no significant difference in the density limit process has been observed. The pedestal density just before the H to L-mode back transition is the same in deuterium and helium plasmas. The H to L-mode back transition is followed by a development of a MARFE [J. Nucl. Mater. 145-147 (1987) 15] which eventually leads to a density limit disruption.
Original language | English |
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Pages (from-to) | 524-529 |
Number of pages | 6 |
Journal | Journal of Nuclear Materials |
Volume | 313-316 |
Issue number | SUPPL. |
DOIs | |
Publication status | Published - Mar 2003 |
Event | Plasma - Surface Interactions in Controlled Fusion Devices - Gifu, Japan Duration: 26 May 2002 → 31 May 2002 |
Keywords
- Boundary plasmas
- Divertor
- Helium
- Operational limits