Optimization of HF- injection at the 2nd harmonic of ECRH on T-10 tokamak in order to obtain high energy content in plasma

Non-traditional scheme of HF-injection has been used in T-10 tokamak for ECRH at the 2nd harmonic of ECR in X-mode. Two HF-launcher systems, with focusing beams, injected power in opposite directions under toroidal angles +/-20˚. Input power from each launcher was about the same (P hf =0.8 ÷ 0.85MWt). Absorbed energy was deposed in central area of plasma column. The new phenomenon has been found in some shots with W-limiter and Li-coating in the regime mentioned above. The spontaneous rise of the electron density nearly in the all plasma column occurs simultaneously with the rise of Te in the wide region (0