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The quasilinear particle flux arising from gyrokinetic instabilities iscalculated in the electrostatic and collisionless approximation, keeping thegeometry of the magnetic field arbitrary. In particular, the flux of electronsand heavy impurity ions is studied in the limit where the former move quickly,and the latter slowly, along the field compared with the mode frequency.Conclusions are drawn about how the particle fluxes of these species depend onthe magnetic-field geometry, mode structure and frequency of the instability.Under some conditions, such as everywhere favourable or unfavourable magneticcurvature and modest temperature gradients, it is possible to make generalstatements about the fluxes independently of the details of the instability. Inquasi-isodynamic stellarators with favourable bounce-averaged curvature formost particles, the particle flux is always outward if the temperature gradientis not too large, suggesting that it might be difficult to fuel such deviceswith gas puffing from the wall. In devices with predominantly unfavourablemagnetic curvature, the particle flux can be inward, resulting in spontaneousdensity peaking in the centre of the plasma. In the limit of highly chargedimpurities, ordinary diffusion (proportional to the density gradient) dominatesover other transport channels and the diffusion coefficient becomes independentof mass and charge. An estimate for the level of transport caused bymagnetic-field fluctuations arising from ion-temperature-gradient instabilitiesis also given and is shown to be small compared with the electrostaticcomponent.

Quasilinear particle transport from gyrokinetic instabilities in general magnetic geometry