自20世纪60年代激光问世以来，强激光脉冲与等离子体之间的相互作用产生的一系列现象就成为了强场物理中的研究重点。啁啾脉冲放大技术提出后，更是为强场物理的发展做出了卓越贡献。超强的激光强度为激光和等离子体之间场的作用推动了很多重要的研究领域。其中高次谐波辐射与阿秒脉冲高能伽马射线的产生是该领域在现时发展阶段的前沿热点，具有非常广泛且迷人的应用前景。

    本论文的主要研究内容是通过二维等离子体粒子数值模拟技术，对超强激光与固体超密锥形靶的相互作用过程进行了粒子模拟的研究，取得以下研究成果：

    首先，基于已知的激光与固体靶相互作用的研究，提出了 90_?碳薄膜锥形靶这样一个新模型。采用线偏振超强激光沿 90_?固体锥形靶的角对角线入射以产生阿秒脉冲。结果发现，一部分等离子体表面的电子会被反射激光场再次加速，在辐射机制主导的作用下产生高次谐波。

    Since the introduction of lasers in the 1960s, a range of phenomena arising from the interaction between intense laser pulses and plasma have been the focus of research in strong field physics. After the chirped pulse amplification technology was proposed, it has made outstanding contributions to the development of strong field physics.The ultraintense laser intensities have driven many important areas of research on the interaction of the field between the laser and the plasma. Among them, the generation of high order harmonic radiation and attosecond pulsed high-energy gamma rays is the frontier focus of this field in the current development stage, and has a very broad and fascinating application prospect.

    The main focus of this thesis is the study of the interaction process between an ultra-intense laser and a solid ultra-dense conical target by a two-dimensional plasma Particle-In-Cell simulation. The details of the study are as follows:

  Firstly, based on the known study of the interaction between laser and solid target, a new model of 90^? carbon thin-film conical target is proposed on the basis of the interaction between laser and plasma. Using linear polarisation intense laser incident along the angular diagonal of a 90^? solid conical target to generate an attosecond pulse, it was found that a fraction of electrons on the surface of the plasma are re-accelerated by the reflected laser field, High-order harmonic generation under the effect of the radiation mechanism.

   Then, these particles were further tracked after the emission of the higher harmonics. Due to the decrease of the ponderomotiveforce, the compressed electron bunches are mainly under the action of the charge separationfield, which accelerates the electrons to tens of MeV. The intense laser pulses and the accelerated electron beams radiate high energy gamma-rays in an attosecond pulse under non-linear Compton scattering.

  Finally, a comparison with the 2D PIC simulation technique revealed that when the laser reaches the side of the conical target, it is similar to as if the laser were directed obliquely at a flat target. Due to the focusing effect of the cone target on the laser, the electron density obtained at the tip of the cone target is ten times higher than that of the planar target.