Abstract
We present the particle-in-cell (PIC) simulation results of the interaction of a high-energy lepton plasma flow with background electron-proton plasma and focus on the acceleration processes of the protons. It is found that the acceleration follows a two-stage process. In the first stage, protons are significantly accelerated transversely (perpendicular to the lepton flow) by the turbulent magnetic field "islands" generated via the strong Weibel-type instabilities. The accelerated protons shows a perfect inverse-power energy spectrum. As the interaction continues, a shockwave structure forms and the protons in front of the shockwave are reflected at twice of the shock speed, resulting in a quasi-monoenergetic peak located near 200 MeV under the simulation parameters. The presented scenario of ion acceleration may be relevant to cosmic-ray generation in some astrophysical environments.
Original language | English |
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Article number | 105201 |
Number of pages | 5 |
Journal | Science China: Physics, Mechanics and Astronomy |
Volume | 58 |
Issue number | 10 |
Early online date | 5 Sept 2015 |
DOIs | |
Publication status | Published - 1 Oct 2015 |
Keywords
- collisionless shock
- Fermi acceleration
- lepton plasma flow
- particle acceleration