1. Keller, W.E., Hammel, E.F.: Annals of Physics10, 202 (1960)
2. Denner, H.D., Klipping, J., Klipping, G., Lüders, K., Menzel, J., Ruppert, U.: Proc. ICEC 7, IPC Science and Technol. Press, Guildford, U.K. 1978, p. 240 and Adv. Cryog. Eng. 25 (1980); see also: Seidel, A.: The German Infrared Laboratory, its overall concept and cooling system, Proc. ICEC 8, IPC Science and Technol. Press, Guildford, U.K. 1980, p. 43
3. For very narrow flow channels, say around 1 ?m, which have near superleak properties, and very low temperatures the heat conductivity of the material contributing significantly and the helium itself begins to show peculiar heat conduction properties, see: Schmidt, R., Wiechert, H.: Z. Phys. B36, 1?12 (1979)
4. This means, contrary to the usually considered zero net mass flow arrangements, that some mass, the vapour, escapes at velocityv
5. For a review of different approaches to the evaporation kinetics problem see: Wiechert, H.: J. Phys. C9, 553 (1976). In this paper we deduce the evaporation rate in a different way