EC RADIATIVE TRANSPORT IN FUSION PLASMAS WITH AN ANISOTROPIC DISTRIBUTION OF SUPRATHERMAL ELECTRONS

The RAYTEC code for electron cyclotron (EC) wave radiative transport modelling of fusion plasmas has been generalised to cover EC radiative transport in the presence of an anisotropic distribution of suprathennal electrons. More specifically, superposed on a Maxwellian bulk, the population of suprathermals is taken to be the sum of a Maxwellian and a distribution which is Maxwellian in energy and has a distribution in the form of a one-sided loss-or anti-loss-cone in pitch angle, such that suprathermals with an excess of momentum either perpendicular or parallel to the magnetic field (as characteristic, respectively, for EC cyclotron wave heating and current drive) can be dealt with. To display the impact of anisotropy, the profile of the net EC wave power density lost from an ITER-like plasma is evaluated as a function of the cone angle for suprathemals localized either at or off the plasma centre. The results thus obtained are discussed in respect to those for an isotropic distribution of the suprathennals as well as those for solely the bulk plasma.