標題: | Coincidence momentum imaging of four- and three-body Coulomb explosion of formaldehyde in ultrashort intense laser fields |
作者: | Tseng, Chien-Ming Fushitani, Mizuho Matsuda, Akitaka Hishikawa, Akiyoshi 應用化學系 Department of Applied Chemistry |
關鍵字: | Coulomb explosion;Intense laser fields;Formaldehyde;Coincidence momentum imaging;Molecular structure |
公開日期: | 1-Oct-2018 |
摘要: | Ion-coincidence momentum imaging of Coulomb explosion of formaldehyde (H2CO) in femtosecond intense laser fields (800 nm, 1.3 x 10(15) W/cm(2)) is performed with two different laser pulse durations (7 fs and 35 fs). In the 7-fs laser fields, the full fragmentation pathway from H2CO4+ -> H+ + H+ + C+ + O+ is identified. The angles between the fragment momenta are well reproduced by a simple Coulomb explosion model from the geometry of neutral formaldehyde, showing that the molecular structure is virtually frozen along the bending coordinates during the multiple ionization. Three-body Coulomb explosion pathways from triply charged states, H2CO3+ -> H+ + H+ + C+ + O+, are observed in both the 7-fs and 35-fs laser fields. Significant changes in the momentum angle distribution and asymmetric energy partitioning between two H+ ions are observed in the 35-fs case, which are attributed to structural deformation prior to the Coulomb explosion in the longer pulse. |
URI: | http://dx.doi.org/10.1016/j.elspec.2018.07.001 http://hdl.handle.net/11536/148163 |
ISSN: | 0368-2048 |
DOI: | 10.1016/j.elspec.2018.07.001 |
期刊: | JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA |
Volume: | 228 |
起始頁: | 25 |
結束頁: | 30 |
Appears in Collections: | Articles |