微重力条件下复杂等离子体中激光诱导马赫锥的三维模拟

Three-dimensional simulation of laser-induced Mach cones in complex plasmas under microgravity conditions

基于三维流体力学模型,研究了微重力条件下复杂等离子体中不同耦合参数形式、屏蔽参数、尘埃粒子表面带电量以及等离子体密度对激光诱导尘埃扰动密度形成马赫锥的影响情况.模拟发现,当屏蔽参数较大时,不同的耦合参数形式对尘埃颗粒扰动密度产生较大影响.此外,激光辐射力平行或者垂直激光移动速度时,马赫锥在三维空间中呈对称或反对称形貌.并且,增大屏蔽参数、减小尘埃粒子表面带电量、减小等离子体密度,都会增强尘埃粒子之间的库仑屏蔽作用,进而使尘埃扰动密度形成的马赫锥更加局域在激光斑点附近,表现为扰动范围缩小,而扰动密度值增大.

The three-dimensional density distribution of dust particles in complex plasma under microgravity condition has received much attention.Based on the three-dimensional hydrodynamic simulation,the influences of different coupling parameters,shielding parameters,charge of dust particles and plasma density on the Mach cone by laser-induced are studied in complex plasma under microgravity conditions.When the shielding parameters are large,it is found that three differert formulas of coupling parameters Γ=Z_(d)^(2)e^(2)/d·T_(d),Γ'=Z_(d)^(2)e^(2)/d·T_(d)exp(-κ)and Γ'=Z_(d)^(2)e^(2)/d·T_(d)(1+κ+κ^(2)/2)exp(-κ)have a great influence on the disturbance density of dust particles,and the simulation results are in better agreement with the theoretical expectations under the third formulas.In addition,when the laser radiation force is parallel or vertical to the laser movement speed,the Mach cone structure is symmetrical or antisymmetric in the three-dimensional space,which is mainly based on the asymmetry of the laser disturbance mode.Besides,increasing the shielding parameters,or reducing the charge of dust particles,or reducing the plasma density,the shielding interaction between the dust particles is enhanced,making the Mach cone formed by the dust disturbance density more localized around the laser spot,which is chara.cterized by narrowing the disturbance range and increasing density value.It is expected that this work can provide some reference for the theoretical and experimental studies of laser-induced Mach cone in three-dimensional complex plasma under microgravity conditions.