Gyrokinetic Approach to the Analysis of Incident Angle Distribution of Ions in a Magnetized Sheath

The distribution of incident angle of ions to the wall surface in a magnetized plasma is studied by using a gyrokinetic model equation and a full‐kinetic particle‐in‐cell simulation code. The model equation is based on the gyrokinetic energy conservation of a plasma with a strong electric field. The dependence of the angular distribution on the magnetic field angle derived from the model equation and the result of particle simulation agree well when the ion thermal Larmor radius is comparable or less than the Debye length. The energy‐fluxweighted averages of the incident angles for various magnetic field strength are studied by using the particle simulation. Reduction of the average angle is observed for weaker magnetic field. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)