A hydrogen condensation pump with a built-in liquefier

Abstract

A description is given of a hydrogen condensation pump of output 3·7 × 10⁴ sec⁻¹ which has its own liquifier. The limiting vacuum is 10⁻⁸–10⁻⁹ mm Hg. The total power consumed (allowing for the liquid nitrogen) is 17 which is less than for oil-diffusion pumps of the same performance.