Damping of Large-Amplitude Plasma Waves Propagating Perpendicular to the Magnetic Field

Computer simulations of magnetosonic waves, velocity-shell instabilities, and upper-hybrid heating show evidence of a general damping mechanism for large-amplitude electrostatic waves propagating perpendicular to a magnetic field: Particles trapped by a wave of frequency $\omega$ and phase velocity $V_{\mathrm{ph}}$ see an electric field $V_{\mathrm{ph}}\times B$, which accelerates them parallel to the wave front until the $v\times B$ force is large enough for detrapping. For $\omega \gg {\omega }_c$, velocities as large as $\left(\frac{\omega }{4{\omega }_c}\right)V_{\mathrm{ph}}$ can be attained, within a time ${\omega }_{c}t\approx \frac{\omega }{4{\omega }_c}$.