7th International Reflectometry Workshop for Fusion Plasma Diagnostics, 9-12 de Maio de 2005, Garching, Alemanha

	Identification of Local Alfvén Wave Resonances with Reflectometry as a Diagnostic Tool in Tokamaks
	A.G.Elfimov, R. M.O. Galvão, L. F. Ruchko, M.E.C.Manso e A.A.Ivanov
	Resumo
	Local Alfvén wave (LAW) resonances are excited in tokamaks by an externally driven electromagnetic field, below ion cyclotron frequency. We show that combination of small power deposition in LAW resonances, swept by plasma density variation or scanned by varying generator frequencies, in combination with detection of the density fluctuations in the LAW resonances by reflectometry can serve as diagnostic tool for identification of the effective ion mass number Aef and q-profile in tokamaks. The idea is based on the simultaneous detection of the position of m=± 1 local AW resonances, which are excited by M/N=±1/±2 antenna modes, and m=0 generated by poloidal mode coupling effect in tokamaks. The m=0 resonance depends only on the effective ion mass number and does not depend on the q-profile, so that the mass number can be determined unambiguously. Then, we can determine q-factor at the position of m=±1 LAW resonances. Using multifluid ALTOK code, we identify mass number in TCABR experiments and demonstrate the possibility of applying this method in Joint European Torus.