Integrated infrared and visible tangential wide-angle viewing systems for surface temperature measurement and discharge monitoring in EAST

摘要

Two newly developed integrated infrared and visible tangential wide-angle (WA) viewing systems (VS) have been mounted in the Experimental Advanced Superconducting Tokamak (EAST) to provide temperature measurement and hot spot monitoring of the plasma facing components (PFC) for machine protection and further physics studies of various plasma parameters such as the scrap-off layer power fall-off length lambda(q), the peak heat flux on the divertor target q(peak) etc. The systems use endoscopes with reflective optics to obtain a wide-angle view (49.5 degrees x 62 degrees). Via endoscope, the 3-5 mu m middle wave infrared camera and the visible camera with spectral range of 400 - 700 nm, the WAVS could provide simultaneous real time infrared and visible image data of the first wall components in the same field of view (FOV). Some key components e.g. the 4.6 GHz lower hybrid wave (LHW) antenna, the ion cyclotron resonance frequency (ICRF) antenna, the high field side region of neutral beam injection in port F, and approximately 78 degrees more toroidal coverage of outer divertor regions with 27 degrees more toroidal coverage of inner divertor regions are firstly covered by the camera system. This paper presents the diagnostic description of the newly developed WAVS and preliminary experimental results observed including fast-ion losses to the inner wall during neutral beam injection (NBI), single edge localized mode (ELM) observation on upper outer divertor, hot spots on antenna guide limiters and temperature and heat flux distribution on the tungsten and graphite divertor targets in EAST.