A new sub-Doppler fluorescence imaging method in studying laser ablation of B atoms at 248 nm

Citation
Jl. Chang et al., A new sub-Doppler fluorescence imaging method in studying laser ablation of B atoms at 248 nm, J PHYS CH B, 105(22), 2001, pp. 5079-5082
Citations number
17
Language
INGLESE
art.tipo
Letter
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHYSICAL CHEMISTRY B
ISSN journal
1520-6106 → ACNP
Volume
105
Issue
22
Year of publication
2001
Pages
5079 - 5082
Database
ISI
SICI code
1520-6106(20010607)105:22<5079:ANSFIM>2.0.ZU;2-#
Abstract
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 similar to1.7 x 10(8) W/cm(2). Two-dimensional velocity distributions of the laser ablate d B(P-2 degrees (1/2,3/2)) atoms are measured. The angular distributions of the ablated B atoms are velocity-dependent. 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 expa nsion. The speed distributions of the B atoms are well fitted to the shifte d Maxwellian functions and are found to be bimodal, including a fast compon ent with a temperature of 1.8 x 10(4) K topping out at 5.8 eV and a slow co mponent of 3.1 x 10(3) K reaching a maximum at 2.8 eV. While a plasma react ion is responsible for the fast component, the slow one results from photoc hemical processes.