纳秒强光场下呋喃的激光电离中高价离子的产生  

Generation of Multi-charged Ions in Laser-induced Ionization of Furan under Intense Nanosecond Laser Fields*

作　　者：孔祥蕾[1] 牛冬梅[1] 罗晓琳[1] 张先燚[1] 张树东[1] 阚瑞峰[1] 李海洋[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所环境光谱学实验室,合肥230031

出　　处：《Chinese Journal of Chemical Physics》2004年第5期513-517,共5页化学物理学报（英文）

基　　金：Projectsupportedbythe 86 3Program (2 0 0 1AA6 4 10 4 0 ;2 0 0 2AA6 4 90 10 )andtheNationalNaturalScienceFoundationofChina (2 0 0 730 4 2 )

摘　　要：利用 2 5ns脉冲Nd :YAG 5 32nm的激光 ,在 10 11W/cm2 的光场强度下 ,用飞行时间质谱对不同条件下呋喃的激光电离过程进行了研究 .当利用氩作为载气时 ,首次观察到了较强的Cn + (n =2～ 4 )和Om + (m =2～ 3)离子信号 .通过测定峰分裂和数值模拟计算的方法可以确定其中C2 + 、C3 + 和C4+ 的最可几平动能分别为 2 1、6 3和 10 0eV ,O2 + 和O3 + 的最可几平动能分别为 2 0和 4 0eV .质谱峰型的分裂现象和激光延迟实验结果表明 ,这些高价离子可能来源于呋喃团簇的库仑爆炸过程 .The photoionization of furan by an intense 25 ns Nd:YAG 532 nm laser has been studied by time-of-flight mass spectrometry. At the laser intensity of 10 10～10 11 W/cm2, multi-charged ions C n+(n=2～4) and O m+(m=2～3) appeared in the mass spectra when argon was used as the carrier gas. From the peak splitting and the numerical analysis, the most probable kinetic energies of C 2+, C 3+ and C 4+ were confirmed to be 21? 63 and 100 eV respectively, and the most probable kinetic energies of O 2+ and O 3+ were confirmed to be 20 and 40 eV respectively. It is proposed that the multi-charged ions come from the Coulomb explosion of furan cluster ions produced by multiphoton ionization of neutral furan cluster.

关 键 词：呋喃 库仑爆炸 高价离子 纳秒激光 

分 类 号：O644[理学—物理化学]