Compact radio-frequency glow-discharge atomic hydrogen beam source

An atomic hydrogen beam source, compatible with ultrahigh vacuum and clean surface conditions, has been developed. Hydrogen atoms (H0) of thermal energy distribution are produced by dissociation of hydrogen molecules in a radio-frequency (rf) glow discharge. The resulting mixture of atoms and molecules is allowed to flow from the discharge vessel to the vacuum test chamber through a capillary, resulting in the formation of a beam. Dissociation fractions [ 1/2 H0/(H2+ 1/2 H0)] of >0.5 and H0 fluxes of >2×1017 H0/s were achieved. Locating the rf power source adjacent to the discharge vessel resulted in a compact device which is easy to maintain and operate.