ANALYSIS OF THE PLASMA EDGE RADIATION BY ICRH ANTENNA.

It is known that a part of the power radiated by ion-cyclotron resonance heating (ICRH) launching structures is directly coupled to the bulk of the plasma whereas another part initially propagates along the plasma edge before leaking into the plasma. This paper discusses the main mechanism of edge radiation: 1) coaxial modes propagating in the vacuum layer between the plasma and the metal wall 2) surfaces waves in the outer plasma gradient. The effect of the geometrical parameters of the antenna on these two forms of radiation is analysed for both the conventional strip-line antenna and the slot antenna.