激光辐照C_(60)分子中光束发散度对产物分布的影响  

Effect of Light Beam Divergence on Ionic Fragments Distributions of C_(60) Irradiated by Nanosecond Laser

作　　者：钱东斌[1,2] 马新文[1,2] 张大成[1,2] 祖凯玲[1,2] 刘惠萍[1,2] 汶伟强[1,2] 

机构地区：[1]中国科学院近代物理研究所,甘肃兰州730000 [2]中国科学院研究生院,北京1000049

出　　处：《光学学报》2009年第6期1577-1581,共5页Acta Optica Sinica

基　　金："西部之光"人才培养计划西部博士科研启动项目资助课题

摘　　要：利用焦距为300 mm和1500 mm的透镜对纳秒激光束进行聚焦,产生了在空间发散度上具有较大差别的两激光束,采用飞行时间质谱计分别测量了两光束诱导C60分子电离和碎裂时的离子产物分布随激光通量的变化特征。实验结果表明,激光束的空间发散度越大,轻碎片离子Cn+(n<25)的总产额、C60分子的碎裂程度以及延迟电离产额随激光通量的变化趋势就越快,延迟电离成分占总电离成分的百分比就越高。该实验结果可用多光子吸收的内能分布理论给予合理解释。Two laser beams with different divergences are obtained using 300 mm and 1500 mm lens. The ionic fragments distributions of the two laser beams are measured by a time-of-flight mass spectrometer. The results show that with the increasing divergence of laser beam, the fragmentation degree of C60, the yield of delayed ionization of C60 and the total yield of the ionic fragment Cn^＋ （n〈25） have steeper change depending on fluences. In addition, the yield of delayed ionization has a larger proportion than direct ionization. The experimental results are in reasonable agreement with the latest prediction by multiple photon absorption theory.

关 键 词：光束发散度 飞行时间质谱计 内能分布 延迟电离 

分 类 号：O561[理学—原子与分子物理]