The electrostatic wake of a superthermal test electron in a magnetized plasma

The electrostatic potential is determined for a test electron with υparallel much-gt υTe, in a uniform magnetized plasma (ωce much-gt ωpe). In the frame of the test electron, part of the spatially oscillatory potential has spherical symmetry over the hemisphere to the rear of the electron and is zero ahead of the electron. A second part of different character, which makes the potential continuous at the plane containing the electron, is oscillatory in the radial direction but decreases almost monotonically in the axial direction