飞秒强激光脉冲与氢团簇相互作用产生的最大质子能量与团簇尺寸的相关性

报道了飞秒强激光脉冲(60 fs,790 nm,2×1016W/cm2)与纳米尺寸的氢团簇(半径rc约为1~3 nm)相互作用,产生的最大质子能量Emax对于团簇半径rc相关性的实验研究结果。从激光-氢团簇相互作用产生的质子的飞行时间谱测量以及团簇尺寸的瑞利散射诊断结果,得到Emax与r2c成线性正比关系,比例系数为0.75,与报道的理论模拟结果一致,表明氢团簇发生纯库仑爆炸。实验结果同时提示,进一步的理论模拟应考虑气体喷流中团簇的尺寸分布。

Size Dependence of Maximum Energy of Protons Produced in the Intense Femtosecond Laser Interaction with Hydrogen Clusters

The dependence of the maximum energy of protons Emax produced in the interaction of an intense femtosecond laser pulse (60 fs, 790 nm, 2×1016 W/cm2) with hydrogen clusters in a gas jet on the square of the cluster radius r2c has been investigated experimentally. The results obtained have established a Emax～r2c relation such as Emax(keV)=1.2+0.32r2c (nm2) with rc ranging from ～1 to 3 nm, in quite good agreement with the reported simulation results, demonstrating that the hydrogen clusters were purely Coulomb exploded under the present experimental conditions. The results also imply that the cluster size distribution in a gas jet should be taken into account in a further simulation study.