Production and electron heating of over-dense plasmas by 2.45 GHz electron Bernstein waves on CHS

Production and heating of over-dense plasmas by 2.45 GHz microwave system under very low field condition was performed and demonstrated on CHS. In this experiment, microwave systems were arranged to aim at taking place mode conversion of launched electron cyclotron wave effectively into electron Bernstein wave (EBW). The power deposition profiles in produced over-dense plasmas were measured directly by using power modulation technique at various magnetic configurations. The power deposition took place dominantly in overdense region. To clarify wave trajectories, power absorption mechanism and mode conversion, a numerical analysis by a ray-tracing method was performed. Calculated ray-trajectories accessed to the region where the experimentally obtained deposition profile has a peak. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)