Measurements of density, surface recombination coefficient, and diffusion coefficient of hydrogen atoms by Lα laser fluorescence spectroscopy

Abstract

The technique of laser fluorescence spectroscopy at the Lyman‐alpha (L_α) wavelength in hydrogen was used to measure the temporally and spatially resolved atomic density, the surface recombination coefficient γ, and the diffusion coefficient DH,H₂ of the atomic hydrogen in molecular hydrogen. At the same time, it revealed a temporal change of γ, probably due to the change of surface number density of trapped hydrogen atoms. The present technique provides a new and powerful means for determinations of values associated with hydrogen atoms by absolute and local measurements of the atoms at the detection limit of extremely low concentrations.