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

作　　者：CUI YunQian SHENG ZhengMing LU QuanMing LI YuTong ZHANG Jie 

机构地区：[1]Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences [2]Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde [3]Key Laboratory for Laser Plasmas (Mo E) and Department of Physics and Astronomy, Shanghai Jiao Tong University [4]IFSA Collaborative Innovation Center, Shanghai Jiao Tong University [5]School of Earth and Space Sciences, University of Science and Technology of China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2015年第10期76-80,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2013CBA01500);the National Natural Science Foundation of China(Grant Nos.11421064,11220101002,11129503 and 11135012)

摘　　要：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 Me V under the simulation parameters. The presented scenario of ion acceleration may be relevant to cosmic-ray generation in some astrophysical environments.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.

关 键 词：particle acceleration Fermi acceleration collisionless shock lepton plasma flow 

分 类 号：O572.2[理学—粒子物理与原子核物理]