1. D. Petrac and P.V. Mason, Proc ICEC 8, Genova, (1980), 97.
2. Superfluid plug as a control device for helium coolant
3. “Superfluid helium transfer flight demonstration using the thermomechanical effect,”;DiPirro;Cryogenics,1986
4. M. DiPirro, F. Fash, and D. McHugh, “Precision measurements of a porous plug for use in COBE,” Proceedings of 1983 Space Helium Dewar Conference, University of Alabama in Huntsville, (1984), 121–132. Other authors have different explanations for the process. U. Schotte, “Flow states and heat transport properties of He II phase separators,” Adv. Cryo. Eng. 21, (1981), 421–430 describes this as thermal “choking”; and J.B. Hendricks and G.R. Karr, “The liquid-vapor transition in porous plug operation,” Adv. Cryo. Eng. 31, (1985), 861–868 states that exceeding the critical velocity of the fluid in the pores is the cause.
5. Alabama Cryogenic Engineering, Huntsville, Alabama 35804, USA.