在宇宙中的宇宙射線或含有能量的粒子所展現能譜的並非熱效應Maxwell分布，而是遵循著冪次定律而分布。為了解釋此非熱效應的宇宙射線能譜，科學家們提出各式各樣的加速機制。然而，我們難以直接從宇宙中的電漿直接測量到絕大部分的物理量，故我們使用高強度雷射系統去模擬宇宙中的空間與電漿來進行實驗。經由一百兆瓦的雷射照射後的氫氣靶材會因尾波加速機制產生非相對論性加速電子，這些被加速的電子可使用架設好的電子能譜儀 (ESM) 所測，而電漿的尾波結構也可以透過影圖與干涉儀觀測到。;Cosmic rays in the universe show power law distributions rather than the Maxwell-Boltzmann distribution. Acceleration mechanisms have been proposed to explain the ultrahigh energy cosmic rays, and wakefield acceleration is one of candidates. However, many fundamental physical quantities are highly challenging to be measured directly in astrophysical plasmas. We use the 100 TW laser facility at the National Central University. By irradiating hydrogen gas jet with the 100 TW laser, relativistic electrons are generated by wakefield acceleration. The accelerated electrons are detected with electron spectrometer, and the plasma structures associated with the wakefields are observed with shadowgraphy. We integrate the energy distribution functions over different shots. The energy distribution functions of energetic electrons show nonthermal tails well represented by power law.