Lienard-Wiechert Beaming and Synchrotron Lobe
What you are seeing: the angular distribution of radiation from a charge accelerated either parallel to or perpendicular to its velocity. As the radiation collimates into a forward cone of opening angle , which is the synchrotron beaming effect. The cyan circle marks the opening angle.
γ (Lorentz)3.0
geometry
γ:2.31/γ:25°
WHAT TO TRY
- Raise the Lorentz factor gamma: the radiation lobe collapses from a broad pattern into a tight forward searchlight of half-angle 1/gamma. Relativistic beaming is what makes synchrotron sources so directional.
- Switch the geometry between acceleration parallel to v and perpendicular to v: the parallel case (linear accelerator) and the perpendicular case (synchrotron) beam into different shapes, both forward-collimated at high gamma.
- Drag to orbit the camera: the lobe is a 3D solid of revolution about the velocity, so spinning it shows the forward pencil that a distant observer catches only as the beam sweeps past.