Demonstration of X-ray Thomson Scattering on Shenguang-Ⅱ Laser Facility

X-ray Thomson scattering technique for diagnosing dense plasma was demonstrated on Shenguang-Π laser facility.Laser plasma x-ray source of titanium He-α lines (～4.75keV),generated by laser beam (1.5kJ/527nm/2ns) heated titanium thin foil,was used as x-ray probe beam.The x-ray probe was then scattered by cold CH foam column of 1g/cm3 density.The scattered radiation at 90 was diffracted by polyethylene terephthalate (PET) crystal and recorded on x-ray charge-coupled device.Well-defined scattering spectra were obtained with good signal to noise ratio.     

Plasma Approach for Generating Ultra-Intense Single Attosecond Pulse

In our previous work,a plasma approach for single attosecond pulse (AP) generation was proposed.A few-cycle relativistic circularly polarized laser pulse will induce a single drastic oscillation of plasma boundary,from which high-order harmonics and furthermore an ultra-intense single AP can be generated naturally after it is reflected.Analytical model and simulations both demonstrate that the process is mostly efficient as the pulse duration is close to the plasma responding time.The effects of plasma density ramp are analyzed here,suggesting that the proposal is still quite efficient with appropriate density gradient in the ramp.At last,a combined approach is employed to obtain single AP with 30 fs incident laser.The relatively large-duration pulse is firstly shortened by a density dropping thin foil,and then reflected from an overdense plasma target.One-dimensional simulation shows that a 600 as single light pulse is generated with peak intensity of 3×1020W/cm2.     

相对论效应产生的高次谐波

用单电子模型研究了相对论效应，特别是相对论坐标变换所引起的高次谐波，得到了谐波产生和激光强度的关系，还得到了谱分布和观测角的关系，特别给出了谱线强度分布的周期和观测角的关系。这一效应可以定性解释相对论强激光和固体靶相互作用所产生的高次谐波     

短脉冲泵浦类锂铝离子X射线激光模拟

建立了适合描述短脉冲激光泵浦类Ｌｉ离子产生Ｘ射线激光的简化流体和原子动力学模型。短脉冲激光泵浦纤维靶产生等离子体的电子密度、电子温度、电离态分布等和驱动激光功率密度、脉宽及纤维靶半径相联系。研究了类Ｌｉ铝离子４ｆ－３ｄ跃迁激光增益系数随时间的演化过程，以及峰值增益和泵浦激光功率、脉宽及纤维靶半径之间的关系。     

The Electron Trajectory in a Relativistic Femtosecond Laser Pulse

In this report, we start from Lagrange equation and analyze theoretically the electron dynamics in electromagnetic field. By solving the relativistic government equations of electron, the trajectories of an electron in plane laser pulse, focused laser pulse have been given for different initial conditions. The electron trajectory is determined by its initial momentum, the amplitude, spot size and polarization of the laser pulse. The optimum initial momentum of the electron for LSS （laser synchrotron source） is obtained. Linear polarized laser is more advantaged than circular polarized laser for generating harmonic radiation.     

利用类锂离子4f－3d跃迁与4d－3p跃迁强度比测等离子体的电子密度的实验研究

利用类锂离子４ｆ－３ｄ跃迁与４ｄ－３ｐ跃迁强度比测等离子体的电子密度的实验研究李儒新，沈百飞，王晓方，陆培详，韩申生，范品忠，张正泉，徐至展（中国科学院上海光机所，上海２０１８００）等离子体的电子密度的测量一直是等离子体基本参数测量最重要的内容之一，...     

类锂硅软X射线激光模拟

类锂硅软Ｘ射线激光模拟沈百飞，王晓芳，徐至展，腾华国，张文琦（中国科学院上海光机所，上海２０１８００）周忠源，潘守甫（吉林大学原子与分子物理研究所，长春１３００２３）类锂离子方案是软ｘ射线激光复合泵浦机制的一个非常重要的方案，复合机制具有所需泵渝光功...     

基于激光引导的静电激波产生单能重离子束

惯性约束聚变的快点火方案、癌症治疗等这些重要的应用均需要单能的离子柬.近来通过激光与等离子体相互作用加速产生高能离子已经成为一个研究热点,因其造价和占用空间都远小于传统加速器.同前已经提出了很多种加速机制,其中靶后鞘层加速较为成熟,实验上已经利用强度为3×1020 w·cm-2的激光产生出最高能量为58 MeV的质子束,也有利用微结构靶产生能散度约为20%的质子束.本文研究的足另一种重要的加速机制,激波加速.     

螺线管传输并聚焦高能质子束的数值模拟

采用3Dparticle-in-cell(PIC)数值模拟方法,研究高品质高能质子束经由脉冲电流螺线管传输并聚焦于远端的情况。模拟结果表明:初始时刻中心能量为250MeV,能散度为10%,空间发散角小于15mrad的质子束,通过长度为760mm、中心磁感应强度为10.87T的通电螺线管,可以被聚焦于距离质子源约2.5m的远端,焦斑横截面直径约为1.2mm,小于模拟初始时刻的1.8mm,质子数目的损失小于3%。研究结果表明利用通电螺线管来传输和调控高能质子束流的方案是可行的。该方案可用于优化质子束流品质,促进激光驱动质子加速在癌症治疗等对质子束单能性和发散角要求较高的领域得到早日应用。