非均匀等离子体中的相对论球形等离子体波  

Relativistic spherical plasma waves in inhomogeneous plasma

作　　者：成丽红 张小波 唐荣安[2] 张爱霞 薛具奎[2] CHENG Li-hong;ZHANG Xiao-bo;TANG Rong-an;ZHANG Ai-xia;XUE Ju-kui(School of Science,Guizhou University of Engineering Science,Bijie 551700,Guizhou,China;College of Physics and Electronics Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China)

机构地区：[1]贵州工程应用技术学院理学院,贵州毕节551700 [2]西北师范大学物理与电子工程学院,甘肃兰州730070

出　　处：《西北师范大学学报（自然科学版）》2022年第5期42-47,共6页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11865014,11765017,11764039);贵州工程应用技术学院高层次人才科研启动项目(G2018004);毕节市科技计划联合基金项目(T[2019]14)。

摘　　要：理论上研究了相对论球形等离子体波和波破裂.研究过程中使用了拉格朗日坐标下的流体方程组和麦克斯韦方程组,根据电子的动量和位移满足的积分方程得到电子的振荡轨迹图,并获得了波破裂时间的估算方法.结果发现,等离子体的非均匀密度参数可以影响电子的振荡形式与周期.当等离子体密度沿着径向线性增加时,电子振荡振幅变小,振荡周期减小,延长了波破裂时间;当等离子体密度沿着径向线性减小时,电子振荡增强,缩短了波破裂时间.调节等离子体的非均匀密度参数,可以实现对等离子体波破裂时间的操控,为激光等离子体加速器中注入合适的电子提供有效方法.Relativistic spherical plasma wave and its wave breaking in inhomogeneous spherical plasma were theoretically studied.The Maxwell and hydrodynamics equations under the Lagrange coordinate were used to derive a wave equation describing the relativistic spherical plasma wave.An integral of the motion was obtained and trajectories of the electron oscillation were shown in the phase of the electron momentum and radius.Based on equation the frequency of electron oscillation,the breaking time was obained.It was found that the plasma density inhomogeneity has strong influence on electron oscillation forms and corresponding frequency.For positive gradient plasma density in radius direction,the electron oscillation becomes weaken and the breaking time increases.For negative gradient plasma density in radius direction,the electron oscillation becomes enhanced,and the breaking time shortens.In negative case,there is a plasma density inhomogeneity critical value beyond which electron periodic oscillations cannot occur.Therefore,the wave breaking time can be controlled by adjusting the inhomogeneous parameter,which providing a method for controllable electron injection in laser-plasma accelerator.

关 键 词：非均匀等离子体 球形等离子体波 波破裂 电子注入 

分 类 号：O53[理学—等离子体物理]