| Popis: |
A satellite in sunlight can charge to substantial negative voltages, even though the photoelectron surface current is typically much larger than the ambient currents in space, because escaping photoelectrons can be blocked by local potential barriers. In this report, we discuss two analytic models for sunlight charging of a rapidly spinning spherical satellite, both of which are based on blocked photoelectron currents: the monopole-dipole model where the spin axis points at the sun and the monopole-quadrupole model where the sun is perpendicular to the spin axis. A comparison is made between the calculated ratio between the maximum and minimum potentials on the surface and measured ratios for eclipse to sunlight charging obtained from satellites in geosynchronous orbit. |
