3He film flow on a round rim beaker

The superfluid properties of thin (100-150 nm) of3He were investigated by measuring the rate at which a beaker of liquid3He emptied itself through the adsorbed film, with the film thickness \u3b4 decreasing as the level dropped. A beaker rim with a semicircular cross-section was used to provide a well defined geometry and to avoid the effects of small scratches that may have affected earlier experiments. The film thicknesses were determined by Atkins' oscillaton measurements of4He films on the same surface. The superfluid transition temperature in the film Tc F was suppressed below the bulk value Tc B, and was close to being described by 2\u3b4/\u3be(Tc F) = \u3c0, as expected for A-phase. The critical current density was more than an order of magnitude smaller than expected for pair-breaking. When a4He monolayer was adsorbed on the substrate, there was no suppresson of Tc F. \ua9 1994 Plenum Publishing Corporation.Peer reviewed: YesNRC publication: Ye