Helium Scattering from a Krypton Film on Graphite

Scattering data are presented for a monoenergetic beam of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ incident on both commensurate and incommensurate Kr films adsorbed on graphite. For the commensurate layer, four bound-state resonance levels are observed, at binding energies 4.67, 1.86, 0.58, and 0.14 meV, which agree with a calculation incorporating three-body interactions. For the incommensurate layer, only the lowest level is identified; its binding energy of 5.2 meV also agrees with the calculation.