The sticking coefficient of atomic hydrogen at T(G) = 1815 K on a Cu (
110) surface has been determined to be 18%. In addition to the buildup
of a chemisorption layer the absorption of atomic H into subsurface s
ites is observed. The subsurface sites are thermally less stable than
the chemisorption sites. Model calculations for the phononic energy tr
ansfer and estimates for the parallel momentum transfer as well as for
electron-hole pair excitation indicate that the first two mechanisms
dominate the accommodation process.