| Hauptseite > Publikationsdatenbank > Radiation pattern and impurity transport in argon seeded ELMy H-mode discharges in JET |
| Journal Article | PreJuSER-23505 |
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2002
IOP Publ.
Bristol
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Please use a persistent id in citations: http://hdl.handle.net/2128/1764 doi:10.1088/0741-3335/44/9/305
Abstract: paper addresses the issues of impurity behaviour during the argon seeding experiments in JET, in which argon and D-2 have been simultaneously puffed in ELMy H-mode discharges to reach high density regimes, maintaining good confinement properties throughout the plasma discharge. The analysis is based mainly on a 1-D impurity diffusion model, which evaluates the impurity transport coefficients in three experimental scenarios.The available experimental data include, as a function of the time, the brightnesses of the soft x-rays and of several impurity lines, the effective charge Z(eff) the profiles of the radiated power and the fully stripped Ar and C ion densities from charge-exchange recombination. From the simulation of these data it is possible to characterize the considered scenarios in terms of high-Z ion increase in the plasma centre and high radiation from the edge. In particular, it has been found that the configuration at high triangularity with continuous D-2 puffing, characterized by an outward impurity pinch velocity, features flat or slightly hollow impurity ion profiles and high radiation from a narrow region at the edge, possibly associated to the presence of a significant neutral density. In this case an edge radiative mantle is established without high radiation from the plasma centre.
Keyword(s): J
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