Filamentation instability in two counter-streaming laser plasmas

The filamentation instability was observed in the interaction of two counter-streaming laser ablated plasma flows,which were supersonic, collisionless, and also closely relevant to astrophysical conditions. The plasma flows were created by irradiating a pair of oppositely standing plastic(CH) foils with 1ns-pulsed laser beams of total energy of 1.7 k J in two laser spots. With characteristics diagnosed in experiments, the calculated features of Weibel-type filaments are in good agreement with measurements.     

“神光-Ⅱ”第九路终端光学系统稳定性分析

 在“神光-Ⅱ”装置上进行先进高能多功能激光束系统(简称第九路)研制工程中，由于在原ICF靶室上又增加了输入“汤姆逊探针光”和“X光背光照明探针光”的锥形真空套筒及其终端光学元件，导致原有靶室结构的变化，可能会引入新的不稳定因素。通过有限元分析方法，建立有限元分析模型，进行优化设计。通过位移传感器测量结果可知，第九路终端光学元件径向窜动所引起的打靶误差最大值为2.110 μm，小于“神光-Ⅱ”靶场终端光学系统的最大允许误差值7.785 μm。