Angle-resolved studies of strong-field ionization and hydrogen elimination from ethylene and ethane
POSTER
Abstract
Intense few-cycle laser pulses are used to ionize C$_{2}$D$_{4}$ and C$_{2}$D$_{6}$ and stimulate dissociation into C$_{2}$D$_{3}^{+}$ $+$ D and C$_{2}$D$_{5}^{+} + $ D, respectively. Velocity map imaging of the ionized fragment ions allows examination of the angular dependence of these processes. In the ethylene example, calculations show that the HOMO, LUMO, and HOMO-1 orbitals are strongly distorted along the C-D bond direction, leading to the creation of a Rydberg orbital near the deuterium atom. The tunneling ionization probability from the Rydberg orbital is high, explaining the experimental observation of enhanced fragmentation along the C-D bond direction. Similar calculations for ethane show qualitative agreement with the measured angular distributions of C$_{2}$D$_{5}^{+}$ fragments. This link between molecular structure, tunneling ionization, and imaging detection can be useful for image-based adaptive control experiments.
*Augustana College personnel are supported by NSF grants PHY-0969687 and EPS-0903804 while JRML is supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Science, Office of Science, US Department of Energy