Diffusion of atoms produced by photodissociation in an I 2 vapour: pressure dependence of surface recombination and a correction of the decay time of the fundamental mode
Year: 2026
Type: article
Abstract: This work investigates, theoretically and experimentally, the spatio-temporal evolution of the density of iodine atoms produced in a cylindrical fused silica cell containing iodine molecular gas. The atoms are generated along the axis of the cell by laser photodissociation at the wavelength 488 nm and their density is monitored using the two-photon absorption laser-induced fluorescence technique. The diffusion coefficient D and the wall-recombination probability γ are determined by fitting a multimode model of atomic diffusion to experimental time variations of the atomic density recorded under various pressures. An improved formula is established for the fundamental-mode decay time, beyond the usual addition of a diffusion time and a recombination time. The diffusion coefficient D of I in I 2 vapour is found equal to 0.048 ± 0.009 m 2 s − 1 at 10 Pa, while the wall-recombination coefficient γ decreases from 0.25 to 0.05 when the pressure increases from 2.7 to 31.1 Pa.
Source: Physica Scripta
Language: English
Subfield: Applied Mathematics
Field: Mathematics
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,400
OpenAlex ID: W7168172814