Experiment of Fundamental ECRH in the GAMMA 10 Central Cell

As an improvement of the central-cell ECRH (C-ECRH) system in GAMMA 10, an ellipsoidal mirror was installed instead of a cylindrical mirror. With this replacement, the microwave beam for ECRH is converged to the GAMMA 10 axis on the resonance surface and Poynting flux reaching the plasma core region becomes about five times larger than the previous one. Effectiveness of this system has been shown in the initial stage of experiment. Finite increment of soft X-ray signal during ECRH operation indicates an increase of the electron temperature. As more improvement, designing a new antenna is now under way.