Emission limited electrostatic atomization and the fine structure constant

Quadropole mass spectrometer measurements are obtained for charged Octoil sprays, at a droplet radius of 0.83 μm. Data are obtained for both emission limit and Rayleigh limit regime. The data revealed that operation in the emission limited regime is a function of inverse relative dielectric constant, coupling parameter r_s, and the inverse fine structure constant f. The values r_s and f and their ratio (r_s/f) involve Planck´s constant, indicating that emission limited spraying is controlled by quantum mechanical processes. The relationship between the energy per surface charge with the droplet diameter of Octoil is also shown.