HE-3 BINDING-ENERGY IN THIN HELIUM-MIXTURE FILMS

We report measurements of the binding energy of dilute coverages of He-3 of He-4 adsorbed films. These energies, when combined with measurements of the energy gap between the ground state and the first excited state of He-3 in the He-4 film, provide the binding of the excited state to the film surface. We find that for 0.1 monolayer of He-3 and for He-4 areal densities 0.21 less-than-or-equal-to n4 less-than-or-equal-to 0.53 angstrom-2, the He-3 binding energies obtained are in reasonable agreement with values calculated using a density functional description of the film for the He-4 coverage dependence of the binding energy.