高温烧蚀初始印记及其瑞利-泰勒不稳定性发展的研究

直接驱动惯性约束聚变中，高温烧蚀初始印记在压缩过程的不稳定性发展中起着重要作用.利用X射线针孔辅助点投影成像法，研究了不同波形激光脉冲驱动下CH平面靶及其瑞利-泰勒不稳定性发展的情况.结果表明，在相同驱动激光能量作用下，初始阶段激光强度越低，上升越缓慢，高温烧蚀初始印记引起的密度调制幅度越大.提高预脉冲强度能显著抑制高温烧蚀初始印记效应. 关键词： 高温烧蚀初始印记 激光脉冲形状 瑞利-泰勒不稳定性 针孔辅助点投影

Imprinting and consequent Rayleigh-Taylor growth

In direct drive inertial confinement fusion， surface perturbations seeded by imprint from laser intensity variations play an important role in Rayleigh-Taylor（RT） growth. Laser imprinting and consequent RT growth in planar CH targets driven by different pulse shapes have been investigated. The experimental results reveal that the range of density modulation induced by laser imprinting is larger when the driving laser has lower foot intensity and rises more slowly. Enhancing the pre-pulse intensity can restrain the effect of laser imprinting notablely.