搜索

x
中国物理学会期刊

面向空间辐射模拟的激光驱动双平面复合靶电子加速研究

CSTR: 32037.14.aps.74.20241639

Laser driven electron acceleration from dual-plane composite targets for space radiation applications

CSTR: 32037.14.aps.74.20241639
PDF
HTML
导出引用
  • 激光驱动的电子束在空间辐射环境模拟领域具有重要的应用价值. 然而, 由于激光直接辐照高密度固体靶所产生的电子束存在能谱可调谐性差、激光能量高等缺点, 限制了其广泛应用. 本文提出了利用激光驱动双平面复合靶电子加速模拟近地空间轨道电子辐射的方案. 研究结果表明, 高密度固体靶能够提供大量低能电子, 其前表面放置的垂直平面靶则提供少量高能电子, 使得所产生的电子束能谱与空间辐射电子能谱非常接近. 为了评价本方案所产生能谱与空间辐射能谱的相似程度, 本文提出一种评价能谱相似程度的评价方法, 该方法可以对两种能谱给出定量评价. 随着垂直平面靶密度增大, 电子加速机制由有质动力加速逐渐过渡到表面有质动力加速, 电子束能谱被有效地调制. 同时, 通过贝叶斯优化给出了最优的靶参数条件, 可以获得与空间辐射能谱更加接近的电子束. 研究结果为激光驱动电子束模拟不同轨道空间辐射环境实验研究提供了理论参考.

     

    Laser driven electron beam has important application value in the field of space radiation environment simulation. However, due to the shortcomings of poor spectrum tunability and high laser energy of the electron beam generated by laser direct irradiation of high-density solid targets, its wide application is limited. In this work, a scheme is proposed to simulate the orbital electron radiation in near-Earth space by using laser driven dual-plane composite target electron acceleration. It is found that the high-density solid target II can provide a large number of low energy electrons, while the vertical plane target I located in the front surface of target II can provide a small number of high energy electrons, which makes the electron energy spectrum very close to that of the space radiation environment. In order to evaluate the similarity between the generated energy spectrum and the space radiation spectrum, a method of evaluating the similarity of energy spectra is proposed, which can describe the local similarity and the global similarity of the energy spectra. For vertical plane target I with low density, the electron acceleration is dominated by the laser ponderomotive acceleration that generates a half-wavelength oscillation. As the density increases, the electron acceleration gradually transitions from the laser ponderomotive acceleration to the surface ponderomotive acceleration, and the electron beam energy spectrum is modulated effectively. Meanwhile, the electron temperature of the generated electron beam is linearly related to the length and density of the target I, and the optimal target parameters are obtained by the Bayesian optimization, and the generated electron beam is much better matched to the space radiation environment. Compared with the scheme of laser driven single-plane target electron acceleration, the proposed scheme has better tunability of energy spectrum and lower requirement of laser intensity. The results provide a theoretical reference for the experimental study of simulating space radiation environments in different orbitals by using laser-driven electron beams.

     

    目录

    /

    返回文章
    返回