Production of 1.25 K 4He without 4He superfluid film

Abstract

A refrigeration process is described which enables the production of a sub‐λ‐point ⁴He temperatures without the production of superfluid. The advantages of the process for zero gravity (0‐g) and low‐noise refrigeration are described. The lowest temperature produced to date is 1.25 K. The process is also useful with other gases for refrigeration; the output temperature is selected by gas type.