Flow state of 3He in adiabatic flow of HeII

Abstract

In adiabatic flow of HeII, the normal fluid components are forced to flow by the action of the superfluid component through vortices. The flow state of 3He , added into the system, in the flow path was studied with the pulsed NMR method in the presence of field gradient. The results show that the flow is almost Poiseuille type in contrast with the highly turbulent state of the superfluid component. The method also directly gives the He flow velocity in the flow path. The results show the existence of the characteristic velocity v c2 predicted by the new-type mutual friction force.