物理化学学报 >> 2005, Vol. 21 >> Issue (10): 1113-1116.doi: 10.3866/PKU.WHXB20051010

研究论文 上一篇    下一篇

乙腈团簇增强的激光高价电离现象的质谱研究

邵士勇;李海洋; 罗晓琳; 肖雪; 牛冬梅; 温丽华; 王宾; 梁峰; 侯可勇   

  1. 中国科学院环境光学与技术重点实验室, 中国科学院安徽光学精密机械研究所, 合肥 230031; 中国科学院大连化学物理研究所, 大连 116023
  • 收稿日期:2005-02-01 修回日期:2005-04-29 发布日期:2005-10-15
  • 通讯作者: 李海洋 E-mail:hli@dicp.ac.cn

Cluster- assistant Multiply Ionization of Acetonitrile by Nanosecond Laser

SHAO Shi-yong; LI Hai-yang; LUO Xiao-lin; XIAO Xue; NIU Dong-mei; WEN Li-hua; WANG Bin; LIANG Feng; HOU Ke-yong   

  1. Key Laboratory of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031; Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023
  • Received:2005-02-01 Revised:2005-04-29 Published:2005-10-15
  • Contact: LI Hai-yang E-mail:hli@dicp.ac.cn

摘要: 利用脉宽为25 ns的脉冲Nd:YAG1064 nm激光, 在1010~1011 W•cm-2强度下, 用飞行时间质谱对乙腈分子束激光电离过程进行了研究, 发现了高价态的原子离子Nq+(q=1~5)和Cq+(q=1~4). 类氦离子N5+、C4+的最可几平动能分别高达566 eV和427 eV. 激光延时以及不同束源压力的实验结果表明, 这些高价离子可能来源于乙腈团簇的库仑爆炸过程. 提出一个多光子电离引发, 逆韧致吸收加热- 电子碰撞电离模型来解释高价离子的产生.

关键词: 乙腈, 团簇, 库仑爆炸, 高价离子

Abstract: The photoionization of acetonitrile seeded in helium is studied by time- of- flight mass spectrometry using a 25 ns, 1064 nm Nd:YAG laser with intensity near 1011 W•cm-2. Multiply charged ions of Nq+(q=1~5) and Cq+(q=1~4) with hundreds of eV have been observed under laser beam irradiation with the densest portion of the pulsed molecular beam. An electron re-scattering and re-colliding ionization model is proposed to explain the generation of those multiply charged clusters under such low laser intensity.

Key words: Acetonitrile, Cluster, coulomb explosion, Multiply charged ion