Radiative boundary discharges with impurity injection and the H-L transition in ASDEX Upgrade
The influence of impurity radiation on the H-L and the L-H transitions is investigated for highly radiative divertor discharges in the ASDEX Upgrade tokamak. The transitions between H and L mode depend on the net heat flow across the separatrix, calculated from the heating power and bolometric radiation profiles. For typical radiative boundary conditions in ASDEX Upgrade, the radiation distribution is dominated by line emission in the vacuum-ultraviolet region and peaks near the separatrix. For the case of neon used as seed impurity, about 2/3 of the main chamber radiation is emitted inside, but closer to the separatrix. Argon seed results in a higher fraction of core radiation, while the line emission is shifted further outside for nitrogen.
Bibliographic Reference: Article: Plasma Physics and Controlled Fusion, Vol. 38 (1996) pp. 2097-2112
Record Number: 199710338 / Last updated on: 1997-04-14
Original language: en
Available languages: en