Electronic Ultra-High Vacuum Pump

Abstract

An ultra‐high vacuum pump has been developed based on the combined effects of ionization, excitation and sputtering. A cold‐cathode discharge in magnetic field is employed with no hot filaments nor moving parts. The ultimate vacuum attainable is not yet known but is probably below 2×10⁻¹⁰ mm Hg. A pumping speed of about 10 liters/sec for air has been recorded at 1×10⁻⁷ mm Hg. The pump replaces liquid nitrogen‐trapped oil diffusion pumps for pumping microwave tubes.