Author/Authors :
Huber، نويسنده , , A and Coad، نويسنده , , P and Coster، نويسنده , , D and Ingesson، نويسنده , , L.C and Itami، نويسنده , , K and Jachmich، نويسنده , , S and Kirschner، نويسنده , , A and Lehnen، نويسنده , , M and Matthews، نويسنده , , G.F and Mertens، نويسنده , , Ph and Philipps، نويسنده , , V and Pospieszczyk، نويسنده , , A and Schweer، نويسنده , , B and Sergienko، نويسنده , , G and Stamp، نويسنده , , M، نويسنده ,
Abstract :
A 2D-tomographic reconstruction of Dα- and C III-emission distribution in L-mode, density limit discharge has been performed and compared with results from other diagnostics (KL2, KS3). The observed emission patterns in a poloidal plane show a strong in–out asymmetry, which depends on local plasma parameter in the divertor. It is shown that the major contribution to Dα-emission, under the observed conditions, lies in excitation processes and that low-energy charge-exchange reactions with neutral deuterium can influence the ionisation balance of carbon and the recorded C III-emission line. The evolution of the intrinsic hydrogen and carbon impurity profiles has been analysed with respect to its dependence on the location of methane fuelling.
