Heavy ion beam probe diagnostic system on JFT-2M

Heavy ion beam probe (HIBP) on JFT-2M has been installed. The diagnostic system is described briefly alone with a detailed description of planned calibration experiments. Two sets of poloidal and toroidal sweepers are used, one set at the entrance port and the other set at the exit port. These are used to measure a potential profile from the edge to the core of the plasma and to reduce the error due to the change of the angle to the energy analyzer. The calibration of the required voltages on electrodes of these sweepers for the potential profile measurement will be performed by the ionization of the injected beams with the neutral gas puffed into the tokamak chamber, with special emphasis on the effects of peculiar behaviors of the double sample volumes and sample volume divergence. It is found that in JFT-2M HIBP these phenomena do not disturb the calibration of the potential measurement. These peculiar behaviors will be useful for accurately determining the location of the observation point.