CCD camera array system for electron density and temperature measurement in the LHD plasma periphery

An image data analysis system using four CCD cameras has been developed for measuring electron density and temperature profiles on divertor legs. The image data are analyzed by image processing software after every plasma discharge. The system was installed in a tangential port, and applied to measurement after the calibration of the CCD sensitivity of each camera. While the electron density on the divertor leg increased with the main plasma density, the decrease of the electron temperature on the divertor leg was observed. These dependencies on the main plasma density agree with the experimental data by a fast moving Langmuir probe and probes embedded in divertor tiles, indicating the availability of the CCD camera array system for plasma parameter measurements on the divertor leg. (author)