3:00 PM - 3:15 PM
[PEM17-06] Electron acceleration by magnetic surfing at non-relativistic shocks
Keywords:electron acceleration, collisionless shock, whistler wave
Electron injection or pre-acceleration is needed to operate diffusive shock acceleration. We have studied electron acceleration at quasi-perpendicular shocks, by performing one-dimensional PIC simulations and analyzing trajectories of energetic electrons. Base on this analysis, we here show a new type of electron acceleration through surfing along the magnetic troughs produced by oblique, phase standing whistler waves embedded in the overshoot magnetic field.
Electron shock surfing acceleration (SSA) is known as energy gain process via the shock motional electric field through surfing with large amplitude electrostatic solitary waves (Hoshino and Shimada, 2002). In SSA the wave electrostatic potential has a peak in the spatial space, while in our model the potential induced by the whsitler has a trough which repels the electron. The Lorentz force created by the magnetic trough well confines the electrons which are efficiently accelerated by the time-varying electrostatic potential with the spatially asymmetric structure. The acceleration terminates when the magnetic trough disappears accompanied by the steepening of the shock ramp during the shock reformation. The maximum attained energy is approximately estimated by the increased electron gyroradius comparable with the whistler wave length. We will apply the magnetic surfing mechanism to Earth's bow shock.
Electron shock surfing acceleration (SSA) is known as energy gain process via the shock motional electric field through surfing with large amplitude electrostatic solitary waves (Hoshino and Shimada, 2002). In SSA the wave electrostatic potential has a peak in the spatial space, while in our model the potential induced by the whsitler has a trough which repels the electron. The Lorentz force created by the magnetic trough well confines the electrons which are efficiently accelerated by the time-varying electrostatic potential with the spatially asymmetric structure. The acceleration terminates when the magnetic trough disappears accompanied by the steepening of the shock ramp during the shock reformation. The maximum attained energy is approximately estimated by the increased electron gyroradius comparable with the whistler wave length. We will apply the magnetic surfing mechanism to Earth's bow shock.