黑腔中高斯型激光束偏折的模拟研究

利用三维激光等离子体相互作用流体程序LAP3D数值模拟研究了高斯光束在均匀等离子体传播过程中的激光束偏折现象,分别考察了激光强度变化和等离子体横向流的流速变化对束偏折的影响。模拟结果表明:当流速接近离子声速时,激光束偏折效应最明显,此时激光偏折程度与激光强度成正比;当流速逐渐小于离子声速时,激光束偏折行为受抑制逐渐减弱;而当流速逐渐大于离子声速时,激光光强包络的变化以衍射效应为主。

Numerical studies of Gaussian laser beam deflection in hohlraum

Beam deflection of a monospeckle laser beam propagating in a plasma with parameters relevant to Inertial Confinement Fusion is investigated using three dimensional Euler laser plasma interaction code LAP3D. Effects of the beam intensity and the speed of the transverse flow on the beam deflection are analyzed. Simulation results suggest that the beam deflection is caused by laser self-focusing and plasma transverse flow. It is found that the beam deflection is evident only when the speed of plasma transverse flow is closer to that of ion acoustic wave and the angle of the beam deflection is in proportion to the laser intensity. When the speed of plasma transverse flow becomes lower than that of ion acoustic wave, the beam deflection is suppressed. When the speed of plasma transverse flow becomes larger than that of ion acoustic wave, refraction effect becomes dominant.