Reflectometry measurements of the m=1 satellite mode in L- and H-mode plamas in...

• Autor(es): Serra, F. ; Manso, M. E. ; Silva, A. ; Matias, José ; Wagner, F. ; Zohm, H. ; Kallenbach, A. ; Varela, P.
• Data: 1992
• Identificador Persistente: http://hdl.handle.net/10198/9032
• Origem: Biblioteca Digital do IPB
• Tipo de Documento: Artigo
• Idioma: Inglês

Descrição

In ASDEX, with strong NB, heating, often a large central m=1, n=1 mode is observed on the SXR emission. For PNBI > 1 MW a mode rotating with the same frequency, the so-called`m=1 satellite`, is seen on the magnetic pick-up coils in the L and H-phases. Magnetic measurement s in the divertor chamber suggest that the satellite mode might be located outside the separatix, on open field lines reaching the diretor /1/. Here we present results from localized microave reflectrometric measurements. The time evolution of the satellite mode frequency is studied for plasmas with different qa and the mode localization is estimated, confirming that is shoud be close to but outside the separatrix. The central toroidal rotation velocities of the plasma can be inferred from the measured frenquencies of the satellite modes.