Effects of supersonic molecular beam injection (SMBI) on plasma performance in Heliotron J

Gas fueling by supersonic molecular beam injection (SMBI) is successfully applied to ECH/NBI plasmas in Heliotron J. The stored energy reached ∝4.5 kJ for a heating combination of ECH (∝0.35 MW) and NBI (∝0.6 MW), which is about 50 % higher than the maximum one achieved so far under the conventional gas-puffing in Heliotron J. After an SMBI pulse for ECH+NBI plasma, two different kinds of perturbation in the radiation profile are caused simultaneously in the center and the peripheral regions. For ECH plasma, an SMBI pulse causes increase or decrease of electron temperature, which seems to depend on the target density. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)