Edge plasma turbulence analysis by collective light scattering in the ToreSupra tokamak

Collective light scattering measurement is a powerful tool for investigatin g fluctuations and their relation with anomalous transport since it allows a direct, discriminating analysis of the turbulent scales. This high scale resolution has a counterpart in a poor spatial resolution, but some localiz ation can be recovered allowing us to discriminate edge from core turbulenc e behavior and to determine turbulence profiles. More information about loc alization can be obtained using temporal dynamics of the scattered signal w hen the fluctuation velocity in the poloidal plane is sheared. Making use o f the consequently separated Doppler shifts, different technics are used to extract localized information from frequency spectra and from the signal p hase derivative. Capabilities of the diagnostic are illustrated by recent r esults obtained on Tore Supra in different regimes. (C) 2001 American Insti tute of Physics.