A new sub-Doppler fluorescence imaging method has been applied to study the laser ablation of B atoms at 248 nm with a power density of ∼1.7 × 10 8 W/cm 2 . Two-dimensional velocity distributions of the laserablated B( 2 P°1 /2,3/2 ) atoms are measured. The angular distributions of the ablated B atoms are velocitydependent; the higher the speed of the B atom is, the more centralized the distribution of the forward peaking will be, indicating that the ablation plume undergoes an unsteady adiabatic expansion. The speed distributions of the B atoms are well fitted to the shifted Maxwellian functions and are found to be bimodal, including a fast component with a temperature of 1.8 × 10 4 K topping out at 5.8 eV and a slow component of 3.1 × 10 3 K reaching a maximum at 2.8 eV. While a plasma reaction is responsible for the fast component, the slow one results from photochemical processes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.