Sensitivity of surface plasmon dispersion and damping to alkali adsorption

I have studied the sensitivity to alkali adsorption of the linear coefficients of surface plasmon dispersion and damping, through the use of self-consistent surface potential barriers which have been shown by Lang to give a good account of the work function changes due to such adsorption. The coefficient of dispersion increases strongly with alkali adsorption on an r_S = 2 substrate, while the coefficient of damping changes less.