• High Power Laser Science and Engineering
  • Vol. , Issue , ()
Qin Chengyu, Zhang Hui, Ji Liangliang, Li Shun, Zhai Shuhua, Li Angxiao, Qian Jiayi, Gui Jiayan, Wu Fenxiang, Zhang Zongxin, Xu Yi, Liang Xiaoyan, Leng Yuxin, Shen Baifei, Li Ruxin
Author Affiliations
  • Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences
  • Shanghai Normal University
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    Abstract

    We report on experimental observation of non-laminar proton acceleration modulated by strong magnetic field in laser irradiating micron-meter Aluminum targets. The results illustrate coexistence of ring-like and filamentation structures. We implement the knife edge method into the radiochromic film detector to map the accelerated beams, measuring source size of 30 ~ 110 μm for proton of > 5MeV. The diagnosis reveals that the ring-like profile originates from low energy protons far off the axis while the filamentation is from the near-axis high energy protons, exhibiting non-laminar features. Particle-in-cell simulations reproduced the experimental results, showing that the short-term magnetic turbulence via Weibel instability and the long-term quasi-static annular magnetic field by the streaming electric current account for the measured beam profile. Our work provides direct mapping of laser-driven proton sources in the space-energy domain and reveals the non-laminar beam evolution at featured time scales.
    Manuscript Accepted: Nov. 19, 2021
    Posted: Nov. 23, 2021