Amano T, Katou T, Kitamura N, Oka M, Matsumoto Y, Hoshino M, Saito Y, Yokota S, Giles B L, Paterson W R, Russell C T, Le Contel O, Ergun R E, Lindqvist P-A, Turner D L, Fennell J F, Blake J B
Department of Earth and Planetary Science, University of Tokyo, Tokyo 113-0033, Japan.
Space Sciences Laboratory, University of California, Berkeley, California 94720, USA.
Phys Rev Lett. 2020 Feb 14;124(6):065101. doi: 10.1103/PhysRevLett.124.065101.
The first-order Fermi acceleration of electrons requires an injection of electrons into a mildly relativistic energy range. However, the mechanism of injection has remained a puzzle both in theory and observation. We present direct evidence for a novel stochastic shock drift acceleration theory for the injection obtained with Magnetospheric Multiscale observations at the Earth's bow shock. The theoretical model can explain electron acceleration to mildly relativistic energies at high-speed astrophysical shocks, which may provide a solution to the long-standing issue of electron injection.
电子的一阶费米加速需要将电子注入到轻度相对论能量范围内。然而，注入机制在理论和观测上一直是个谜。我们通过磁层多尺度对地球弓形激波的观测，给出了一种用于注入的新型随机激波漂移加速理论的直接证据。该理论模型可以解释在高速天体物理激波中电子被加速到轻度相对论能量的现象，这可能为长期存在的电子注入问题提供一个解决方案。
