The effective thermal diffusivity, χeff, deduced from thermal wave propagation often differs from values derived from power balance (χPBeff). For example, on DITE the values (χMODeff) deduced from modulated heating studies using fundamental cyclotron absorption are somewhat higher than χPBeff. Furthermore χMODe depends only weakly on ne in contrast to χPBeff which falls with ne. A possible explanation of such discrepancies between χMODeff and χPBeff is that modulation of the density caused by the modulated heating, which is not taken into account in the analysis, may affect the propagation of the thermal wave. This paper assesses the magnitude of the density modulation produced by modulated ECRH and the extent to which the experimental results can be reconciled with theory.
|Title of host publication||Proceedings 16th European Conference on Controlled Fusion and Plasma Physics, Venice|
|Number of pages||1|
|Publication status||Published - 1 Jan 1989|