1:30 PM–3:30 PM, Thursday, May 19, 2005
Burnham Yates Conference Center - Arbor
Chair: C. L. Cocke, Kansas State University
2:06 PM–2:18 PM
A.M. Sayler
P.Q. Wang
K.D. Carnes
B.D. Esry
I. Ben-Itzhak
(J.R. Macdonald Laboratory, Department of Physics, Kansas State University)
Laser-induced dissociation of O$_{2}^{+}$ has been experimentally studied using ultrashort ($\sim $50 fs) intense ($\sim $10$^{14}$ W/cm$^ {2})$ laser pulses at 790 nm. The O$^{+}$ and O fragments are measured in coincidence with a 3-dimensional momentum imaging system, which provides both angular and kinetic energy release (KER) distributions for dissociation. By analyzing the angular distribution of a specific range in the KER spectrum, the dissociation pathway may be deduced. In particular, a single photon parallel transition ($\Delta \Lambda $=0) is expected to have a cos$^{2}$\textit{$\theta $} distribution, while a perpendicular one ($\Delta \Lambda $=1) leads to a sin$^{2}$\textit{$\theta $} distribution. Therefore, a dissociation pathway requiring the exchange of $n \quad \Delta \Lambda $=0 photons and $m \quad \Delta \Lambda $=1 photons is expected to have a cos$^{2n}$\textit {$\theta $}sin$^{2m}$\textit{$\theta $} distribution. Thus, knowing $n$ and $m$ along with the KER range allows a plausible identification of the dissociation pathway.