Details

Autor(en) / Beteiligte

• Delzanno, Gian Luca
• Roytershteyn, Vadim

Titel

High-Frequency Plasma Waves and Pitch Angle Scattering Induced by Pulsed Electron Beams

Ist Teil von

• Journal of geophysical research. Space physics, 2019-09, Vol.124 (9)

Ort / Verlag

United States: American Geophysical Union

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Cherenkov radiation from a pulse of charge propagating along the magnetic field in a magnetized plasma is analyzed using theory and fluid–kinetic simulations. Besides radiation into whistler modes, the subject of many previous investigations in laboratory and space, radiation can occur through extraordinary (X) modes. Theory and simulations demonstrate that X mode radiation efficiencies can be orders of magnitude higher than those into whistler modes. Test particle simulations of the dynamics of energetic electrons in the beam–generated wavefield show that X modes can also induce pitch angle scattering much more efficiently than whistlers. While coherence effects associated with spreading of realistic beam pulses may limit the size of the X mode source region, a simple model of beam dynamics suggests that the size of this region could be substantial (hundreds of meters for ionospheric conditions). Furthermore, these results have potentially important implications for many problems, including understanding losses in the near–Earth environment and radiation belt remediation.