Investigation of ICRF Heating Effect in Anchor Region on GAMMA 10/PDX

Abstract

To investigate end-loss plasma control, several heating operations were carried out using ion-cyclotron range of frequency (ICRF) heating systems in GAMMA 10/PDX. In anchor region, one of the important heating positions to control the end loss particle and heat fluxes, excited ICRF waves are measured as the density fluctuations using an upgraded reflectometer system and the detailed radial profiles are observed. The efficiency of anchor heating was changed using the phase control between two antennas installed in the anchor and/or the central region. The interference of two waves during a phase-control ICRF heating has been directly measured inside the plasma. In addition, several phase dependencies were observed using absorption methods with photodiode in anchor region.