Closed cycle 4He sorption refrigerators are an increasingly popular choice for remote cryogenic operations. The presence of a superfluid film on the inner walls of the evaporation pot limits their performance. We present a simple model of the gas, film, and heat flow in a 4He sorption refrigerator, taking into account the effects of an orifice to limit superfluid film flow. The model serves as a useful guideline for optimizing cryogenic performance. We also present a diagram of hold time vs. steady state temperature as a function of the radius of the orifice and compare the model to measurements.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)
- He II systems (E)
- Sorption coolers (E)
- Superfluid helium (He II) (B)