激光等离子体相互作用的数值模拟_图文

1、第19卷第12期2007年12月强激光与粒子束HIGH POWER LASER AND PARTICLE BEAMSV01.19。No.12Dec.。2007文章编号:lOOl一4322(2007122039一04激光等离子体相互作用的数值模拟张海鸥1,王琨2,王桂兰2(1.华中科技大学数字装备制造与技术国家重点实验室,武汉430074;2.华中科技大学塑性成形模拟与模具国家重点实验室,武汉430074摘要:基于激光等离子体相互作用的复杂物理过程的数学模型,采用P1C方法分别研究了P极化和S 极化非均匀短脉冲强激光入射均匀分布的稠密等离子体时引起的空泡、成丝等物理现象。模拟了激光脉冲在真空中的

2、3维传播形貌。由3维密度分布图发现:激光产生的巨大的有质动力向两侧推动粒子,形成等离子体密度通道;当激光脉冲入射等离子体区域后,纵向加速的电子速度峰值出现在电流峰值处。关键词:激光等离子体;数值模拟;激光脉冲形貌;脉冲宽度中图分类号:TN248.7;0242.1文献标识码:A激光等离子体相互作用物理是随着激光技术、激光聚变以及激光与等离子体相互作用研究的刺激而发展起来的新兴学科1。由于相对论激光等离子体相互作用过程具有强的非线性,波一粒子相互作用复杂且难以测试,解析求解十分困难,因此粒子模拟成为了其重要的研究手段之一2。在等离子体数值模拟方面和E1dridge 等人33创立了一种在微型计算机上

3、易于实现的粒子模拟方法,S.Mahalingam等41采用此方法模拟了离子引擎内的放电腔内的 2042强激光与粒子柬第19卷3结论本文通过对激光等离子体相互作用的数值模拟,研究了P极化,S极化强激光入射稠密等离子体的典型物理过程以及脉冲变化情况。结果表明当激光脉冲入射等离子体区域后,纵向加速的电子速度峰值出现在电流峰值处,这是激光与等离子体相互作用后进人等离子体中的激光波长会变长的物理现象以及局域振荡电子加热机制基本吻合。P极化和S极化激光分别与等离子体相互作用的电子在纵向速度峰值的出现位置相同,但s极化激光产生了成丝效应、空泡等不同现象。参考文献:1YinY.The research of

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10、cillating electron heating mechanism during laser plasma interaction.HigPo伽r LnsPr4打d Pn仃纠P Bms, Z005,17(1:8387Numerical simulation of laser plasma interactiOnZHANG Hai-oul,WANG Kun2,WANG Gui-lan2(1.S口8K8y Ln6Dr口ory o,Digi口Z M口,l础.厂nc“ri行g E白“ip,ne行口竹d T_c行DZDgy,H“n2o咒g Lki世rsn3,o,SciP孢ce口挖d丁_c卵oZog

11、y,7l血口竹430074t C撬i,m;2.S口fP KPy Ln6曰,-口tory o,Pz口5ic.f砀门"i行g Si,n“Z口fiD,z D,SciP,2cP n咒d:nc恕ozogy,H“口l血ong Uhi口er5ify o,SciP行ce口佗d了c.l咒oZogy,肌口竹430074,(流i72nAbstract:A mathematical model was developed to investigate the complex physical process of laser plasma interaction,adopting the PIC(parti

12、cleirl-cellapproach to study the phenomena when heterogeneous ultrashort and ultra?high laser pulse propagated thIDugh overdense plasma.Through the simulation of3D laser pulse appearance in vacuum,it was found that a channel was formed due to the extremely large pondemnlotive force associated with laser pulse.The lengthways electron velocity appeared in the position of the peak electric current intensity and