Charging of spinning insulating objects by plasma and photoemission

The charging of spinning insulating objects by plasma and photoemission is studied in two spatial dimensions with the particle-in-cell method. Unidirectional photon flux, different angular velocities of the object, and different plasma flow speeds are considered. Photoemission can lead to a positive total charge and electric dipole moment on the object. The spinning of the object redistributes the surface charge and leads to asymmetric potential barriers near the object. The total charge on the object oscillates in time with the period matching the period of the object rotation. The plasma potential and density in the vicinity of the object oscillate with the same frequency. For flowing plasmas, the wake in the ion density is conspicuous behind a positively charged object. The time averaged charge on the object depends on its angular velocity. Citation: Miloch, W. J., and S. V. Vladimirov (2009), Charging of spinning insulating objects by plasma and photoemission, Geophys. Res. Lett., 36, L18110, doi: 10.1029/2009GL040337.