Abstract
A calculation is presented of the relaxation rate, T11, in a dilute gas of spin-polarized H atoms residing on a He4 film. Included in this treatment is the large spatial extent of the surface wave function. A surprising result is that the complete anisotropy of T11, in which T11 is zero for the magnetic field perpendicular to the surface as expected for a purely two-dimensional calculation, survives this general three-dimensional treatment.