THEORETICAL-ANALYSIS OF AN EXPERIMENT TO MEASURE THE CONDENSATE FRACTION IN SUPERFLUID HE-4

We examine the theoretical analysis of an experiment proposed by one o f us to observe the condensate fraction of helium four by firing low e nergy pulses of helium atoms at suspended droplets of the superfluid a nd observing the resulting emission of helium atoms from the fluid. Th e basic approach to such an analysis is to find the many body ground s tate wave functions of liquid helium with N + 1 particles and the appr opriate boundary conditions for one particle, infinitely far away from the surfaces on the right and left sides of the fluid sample. We char acterize the observed rate in terms of the transmission coefficient fo r the process by which a helium atom appears on the right as a consequ ence of an incident particle impinging on the fluid from the left with momentum hkBAR.