Electron Cyclotron Emission Refraction Effects during Edge Localized Modes
نویسندگان
چکیده
During ‘Type III’ ELMs on Alcator C-Mod, electron cyclotron emission (ECE) diagnostics show brief signal drops of second harmonic X-mode and signal increases of fundamental harmonic O-mode. These are explained in terms of refraction effects and found to be useful to infer the associated ELM geometrical dimensions. A new ray tracing code, which can accommodate poloidal variations, has been developed for this investigation. The ELMs are modeled satisfactorily as a density loss from a poloidally elongated region. PACS numbers: 42.15.-i,52.25.Sw,52.55.Fa,52.70.Gw Submitted to: Plasma Phys. Control. Fusion ECE Refraction Effects during ELMs 2
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