Two-stage acceleration of interstellar ions driven by high-energy lepton plasma flows

Cui, YunQian and Sheng, Zheng-Ming and Lu, QuanMing and Li, YuTong and Zhang, Jie (2015) Two-stage acceleration of interstellar ions driven by high-energy lepton plasma flows. Science China: Physics, Mechanics and Astronomy, 58 (10). 105201. ISSN 1869-1927

[img]
Preview
Text (Cui-etal-CSPMA-2015-Two-stage-acceleration-of-interstellar-ions-driven-by)
Cui_etal_CSPMA_2015_Two_stage_acceleration_of_interstellar_ions_driven_by.pdf
Accepted Author Manuscript

Download (2MB)| Preview

    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.