Effects of electron temperature on dielectric function and localization of laser beams in underdense collisional plasma

Effects of electron temperature on dielectric function and localization of laser beams in underdense collisional plasmas are investigated. Simulation results show that the electron temperature has a strong effect on the dielectric constant and the laser beam localization. It is observed that due to the influence of the electron temperature, the dielectric function presents some interesting and complicated nonlinear variations, and gives rise to the laser beam localization. Moreover, the amplitudes of the beam width and the beam intensity are subjected to continuously oscillatory variation in the region of localization. In addition, the effects of several parameters on the dielectric function and the beam localization are discussed.     

高斯型激光圆孔衍射中的光束畸变调控研究北大核心CSCD

从光波衍射的基本理论出发,利用高斯型分布的激光束,研究开普勒望远镜系统在衍射过程中光束畸变调控方法。利用中阶Zernike多项式构建像差函数法来模拟望远镜系统中的四叶畸变现象,并将该Zernike因子引入光学系统中弥补畸变效果。研究发现,波长和孔径会对奇异光强的分布产生明显的影响,波长增大的时候会改变光斑的形状,孔径会影响光斑强度和尺寸,11阶的Zernike四叶形变因子可以抵消望远镜系统的畸变现象。     

强激光与磁化等离子体作用中有质驱动对电子的加速研究

通过利用龙格一库塔方法分析了强激光与磁化等离子体中有质驱动对电子的加速问题。研究发现在磁化等离子体中，有质驱动使得电子沿轴方向发生横向振荡，电子获得高的能量增益，而在等离子体中产生的自生磁场引起的共振进一步加速了电子，使电子能量增益进一步提高。且最终电子能量趋向一个稳定值，电子在有质驱动作用下自动喷射出来，这在实际应用中容易控制，避免了使用抽取高能电子的提取器，这为新型台式加速器的设计提供了有益的理论指导。     

Perturbation Effects of Ion Screening to Leptons in Type-II Supernova

Based on the new progenitor stars model, the influence of ion screening is investigated. The simulation results show that ion screening has weak perturbation effects to the leptons in type-II supernova explosion. Ion screening decreases slightly the fraction of leptons and prolongs slightly the shock propagation time. Moreover, simulation results are shown that ion screening increases the total energy loss and reduces the shock energy, eventually decreasing of explosion energy and becomes a negative factor to supernova explosion. In addition, comparison of slight perturbated variation of ion screening to leptons, but simulation results＂ show that ion screening affects obviously explosion energy of type-II supernova, hence, it can also confirm that the variation of leptons is very sensitive to energy in supernova explosion.     

不可思议的脉冲星

在浩瀚的宇宙中,存在着许许多多的不同种类的星体,在这些星体中,有我们熟悉的绿色家园行星——地球,能量之母的恒星——太阳,以及拖着长长尾巴的彗星等等。但是在众多的星体中,有些星体并不为人们所熟悉,这里就有诸如白矮星、红巨星、超新星、脉冲星和黑洞等等,这些不为人熟悉的星体中,它们都有着与平常星体许多不同寻常的地方,有些方面是我们常人无法想象的,在这众多的不同寻常的星体中,有一种星体它不仅在宇宙学的发展中具有划时代的意义,