Open AccessMultiple ionization of oxygen studied by coincident measurement
Author(s) -
Zhifeng Wu,
Chengyin Wu,
Xianrong Liu,
Yunquan Liu,
Yongkai Deng,
Qihuang Gong
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.010395
Subject(s) - ionization , excited state , atomic physics , ion , laser , physics , double ionization , optics , pulse duration , quantum mechanics
We experimentally study double and triple ionization of oxygen using a reaction microscope. The kinetic energy releases (KERs) and angular distributions are obtained through coincidentally measuring the ionic fragments of doubly or triply charged parent ions. The pathway O(2+)2 ? O (+) O(+)?proceeds through some excited electronic states. The KERs exhibit definite structures independent of the laser intensity and the pulse duration. However, the angular distribution of coincident O(+) reflects the symmetry of the highest occupied molecular orbital (HOMO) only for few-cycle laser pulses at low intensity. The pathways O(2+) 2 --> O(2+) +O and O(3+) 2 --> O(2+) + O(+) occur through some repulsive states. The KERs show a single broad peak and decrease with increasing the pulse duration. The decrease of KER comes from the stretch of the internuclear distance in intense laser fields.