Development of a hyperthermal oxygen‐atom generator

A source that is compact, durable and mounts on a standard standard ultrahigh vacuum (UHV) flange has been developed for the generation of hyperthermal oxygen atoms. In this source oxygen atoms permeate through an Ag membrane held at 500°C and are then emitted toward the target from the vacuum side of the membrane by electron‐stimulated desorption. The current prototype model generates useable O‐atom fluxes of ∼10 12 atoms cm −2 s −1 , and future modifications should increase this flux by 1–3 orders of magnitude. Based on the O + energy distribution, the average O neutral energy is ∼5 eV with a fairly broad distribution (full width at half‐maximum ∼3.6 eV). The information required for the development of this source and the design of the source are prsented.