Flow of 3He-B through narrow channels

The critical current Jc of superfluid 3He-B through 0.8-μm-diam channels has been measured. For small currents the pressure difference ΔP=0 along the flow channels within the resolution, implying small or zero dissipation. ΔP grows rapidly with increasing current above Jc; a clear transition to dissipative flow is thus observed. The temperature dependence of Jc indicates that the superfluid density and the critical temperature are reduced inside the narrow flow channels.Peer reviewe