The moment approach to solve the drift-kinetic equation for impurity ions in the plasma edge region
In the plasma edge region the fluctuation level of electromagnetic fields and plasma parameters is rather high and cross-field transport is dominated by drift motion and anomalous diffusion-convection processes. In the drift-kinetic equation, electromagnetic field fluctuations introduce mixed derivatives of the guiding-centre distribution function with respect to space and velocity coordinates, complicating the solution considerably. A direct solution with arbitrary non-Maxwellian source functions, as in the case of impurities sputtered from a limiter or divertor target, has to be sought by numerical methods. For source functions not deviating too far from a shifted Maxwellian, as in the case of impurity ions fed into the scrape-off layer by recycling from the plasma core or by ionisation of thermally released wall impurities, the moment solution method appears a reasonable alternative. This is discussed in relation to local and non-local transport relations in the presence of anomalous cross-field transport.
Bibliographic Reference: Article: Contributions to Plasma Physics, Vol. 32 (1992) No. 3-4, pp. 290-296
Record Number: 199310276 / Last updated on: 1994-11-29
Original language: en
Available languages: en